ASTRONOMY 


QB43 
i& 


IX 

POPULAR  ASTRONOMY. 

BY 

SIMON  NEWCOMB,  LL.D., 

PROFESSOR  U.  S.  NATAL   OBSERVATORY,  AUTHOR    OF   "  THE  A  B  C   OF   FINANCE." 

With  One  Hundred  and  Ticdve  Engraving*,  and  Five  Maps 
of  the  Wars. 

8vo.  Oloth,  $4  GO. 


The  grpo't  reputation  which  the  author  of  this  work  has  merited  and 
enjoys,  both  in  this  country  and  hi  Europe,  is  a  sufficient  guarantee  of  its 
excellence.  *  *  *  He  has  dwelt  especially  upon  those  topics  which  have 
just  now  a  popular  and  philosophic  interest,  carefully  employing  such  lan- 
guage and  such  simple  explanations  as  will  be  intelligible  without  labori- 
ous study.  Technical  terms  have  as  much  as  possible  been  avoided.  Such 
as  were  employed  of  necessity,  and  many  that  occur  elsewhere,  have  been 
fully  explained  in  a  copious  glossary  at  the  end  of  the  book.  With  its 
abundant  aid,  the  reader  cannot  fail  to  derive  both  pleasure  and  entertain- 
ment from  the  study  of  what  is  the  most  ancient  as  well  as  the  most  ele- 
vating and  inspiring  of  all  the  natural  sciences.  *  *  *  Professor  Newcomb, 
thro^hlWtrthi^^ltqfe' Volume,  preserves  his  well-known  character  as  a 
writer  who,  in  treating  of  scientific  subjects,  fully  understands  the  art  of 
bringing  them  within  the  range  of  popular  comprehension.  Although  his 
book  is  a  valuable  addition  to  scientific  literature,  it  is  fully  calculated  to 
hold  the  attention  of  the  general  reader. — N.  Y.  Times. 

The  problem  of  adapting  the  facts  and  principles  of  a  most  intricate 
science  to  the  understanding  of  the  ordinary  reader  has  been  earnestly 
undertaken  and  successfully  solved  in  this  work.  *  *  *  The  entire  volume 
bespeaks  the  well-known  ability  of  its  author,  and  furnishes  a  new  title  to 
his  world-wide  reputation. — Boston  Transcript. 


M298784 


NewcomVs  Popular  Astronomy. 


Professor  Newcomb  carefully  avoids  the  temptation  held  out  to  him  bj 
many  parts  of  the  subject  to  write  for  effect ;  he  keeps  always  faithfully 
to  his  purpose,  setting  forth,  with  respect  to  every  subject  discussed,  the 
history  of  the  investigations  made,  the  positive,  certain  results  attained, 
and  the  conjectures  which  astronomers  have  founded  upon  these  results, 
together  with  the  reasoning  on  which  each  conjecture  rests  and  the  objec- 
tions  that  exist  to  its  acceptance.  He  is,  in  a  word,  singularly  conscien- 
tious and  perfectly  frank ;  but  the  subject  itself  is  so  full  of  wonders  that 
even  when  treated  in  this  calm,  scientific  spirit,  its  discussion  is  entran- 
cingly  interesting;  and  Professor  Newcomb's  work,  written  as  it  is  in  a 
perfectly  clear,  simple,  and  direct  style,  >  likely,  we  think,  to  become  more 
than  ordinarily  popular. — N.  Y.  Evening  Post. 

The  book  has  the  great  merit  of  a  simplicity  that  never  wearies  the 
reader's  attention.  It  presents  the  newest  as  well  as  the  old  discoveries, 
and  is  free  from  the  errors  which  mar  most  of  the  treatises  on  astronomy 
that  are  designed  for  non-professional  use.  Ordinary  readers  will  appre- 
ciate the  circumstance  that  no  mathematical  formulas  are  employed.  *  *  * 
In  each  division  of  the  work  the  history  of  discovery  is  made  to  subserve 
the  purpose  of  explanation.  *  *  *  Step  by  step  the  reader  is  led  toward  the 
theories  of  Copernicus,  Kepler,  and  Newton,  and  is  shown  why  and  how 
their  hypotheses  best  explained  the  facts  of  observation,  which  have  been 
already  detailed.  A  great  advantage  is  thereby  gained  o^er  ordinary  trea- 
tises of  astronomy,  which  present  the  recent  knowledge  first,  and  either 
give  the  facts  unsupported,  or  press  their  acceptance  by  means  of  the 
stern  logic  of  geometry.  In  Professor  Newcomb's  work  the  great  truths 
grow  slowly,  and  can  be  measured  as  they  grow. — N.  Y.  Tribune. 

The  author  is  a  master  of  all  the  theories  and  lore  of  his  beloved  sci- 
ence, and  he  has  at  command  the  unrivalled  instruments  of  the  United 
States  Naval  Observatory  at  Washington.  He  is  an  unwearied  investiga- 
tor and  professional  enthusiast  (in  the  best  sense  of  the  word),  and  writes 
an  English  which  all  people  can  understand.  Parade  and  pedantry  are 
wholly  absent  from  this  work. — jV.  Y.  Journal  of  Commerce. 

Any  person  of  average  intelligence  can  take  this  volume,  and  in  a  month 
or  two  become  an  intelligent  observer  of  the  worlds  around  us. — Christian 
Intelligencer,  N.  Y. 


NewcomUs  Popular  Astronomy. 


This  is  one  of  those  books  which  deserve  and  are  sure  to  receive  a  hearty 
welcome :  a  full  and  accurate  resume  of  the  subject  treated,  prepared  and 
brought  down  to  date  by  one  who  is  a  master  of  the  science,  and  at  the 
same  time  a  clear  and  vigorous  writer.  It  is  a  book  which  ought  to  be  in 
the  library  of  every  intelligent  person  as  a  standard  authority,  safely  to  be 
referred  to  on  any  topic  within  its  scope ;  and  yet  it  is  not  heavy  or  dull, 
but,  for  the  most  part,  as  readable  and  interesting  as  a  work  of  fiction. 
*  *  *  The  work  is  neither  abstruse  and  dry,  nor,  on  the  other  hand,  is  it 
puerile  and  fanciful,  as  sometimes  happens  when  savans  attempt  to  popu- 
larize their  favorite  sciences,  and  write  down  to  what  they  conceive  to  be 
the  level  of  the  common  intelligence.  The  plan  is  logical,  the  due  propor- 
tions of  different  portions  of  the  subject  are  observed,  and  the  style  is 
clear,  forcible,  and  sufficiently  picturesque  and  stimulating  to  keep  the 
attention  without  effort. — Professor  CHARLES  A.  YOCNG,  in  tfie  Independent, 
N.  Y. 

It  is  only  rarely  that  a  great  mathematical  astronomer  condescends  to 
write  books  for  the  people ;  and  if  he  does,  in  four  cases  out  of  five,  what 
he  writes  is  unintelligible  to  all  but  a  very  few.  Investigators  seldom  have 
either  the  disposition  or  ability  to  communicate  what  they  know  to  the 
world  in  general.  To  this  rule,  however,  there  are  happy  exceptions ;  and 
among  them  must  be  counted  Professor  Xewcomb,  whose  Popular  Astron- 
omy is  undoubtedly  the  best  work  of  its  kind  in  the  English  language. 
Its  arrangement  is  logical,  its  statements  are  accurate,  its  reasonings  clear, 
and  its  style  simple,  perspicuous,  and  sufficiently  picturesque.  Through- 
out the  book  it  is  everywhere  evident  that  great  care  has  been  taken  to 
secure  exact  and  perfect  truthfulness  of  representation:  facts  are  kept 
distinct  from  fancies,  and  theories  and  speculations  stand  for  just  what 
they  are. — Sunday  School  Times,  Philadelphia. 


PUBLISHED  BY  HARPER  &  BROTHERS,  NEW  YORK. 

Sent  by  mail,  postage  prepaid,  to  any  part  of  tJie  Untied  States,  on 
receipt  of  $4  00. 


THI  ¥YXHI 

THI    AFAnHTHI 

ASTPACTOYSHI 

KAI 

ISAITEAQI 


PREFACE. 


ALL  sciences  are  making  an  advance,  but  Astronomy 
is  moving  at  the  double-quick.  Since  the  principles  of 
this  science  were  settled  by  Copernicus,  four  hundred 
years  ago,  it  has  never  had  to  beat  a  retreat.  It  is  re- 
written not  to  correct  material  errors,  but  to  incorporate 
new  discoveries. 

Once  Astronomy  treated  mostly  of  tides,  seasons,  and 
telescopic  aspects  of  the  planets;  now  these  are  only 
primary  matters.  Once  it  considered  stars  as  mere  fixed 
points  of  light ;  now  it  studies  them  as  suns,  determines 
their  age,  size,  color,  movements,  chemical  constitution, 
and  the  revolution  of  their  planets.  Once  it  considered 
space  as  empty ;  now  it  knows  that  every  cubic  inch  of 
it  quivers  with  greater  intensity  of  force  than  that  which 
is  visible  in  Niagara.  Every  inch  of  surface  that  can  be 
conceived  of  between  suns  is  more  wave-tossed  than  the 
ocean  in  a  storm. 

The  invention  of  the  telescope  constituted  one  era  in 
Astronomy  ;  its  perfection  in  our  day,  another ;  and  the 
discoveries  of  the  spectroscope  a  third — no  less  impor- 
tant than  either  of  the  others. 

While  nearly  all  men  are  prevented  from  practical 
experimentation  in  these  high  realms  of  knowledge,  few 


viii  PREPACK 

have  so  little  leisure  as  to  be  debarred  from  intelligently 
enjoying  the  results  of  the  investigations  of  others. 

This  book  has  been  written  not  only  to  reveal  some 
of  the  highest  achievements  of  the  human  mind,  but 
also  to  let  the  heavens  declare  the  glory  of  the  Divine 
Mind.  In  the  author's  judgment,  there  is  no  gulf  that 
separates  science  and  religion,  nor  any  conflict  where 
they  stand  together.  And  it  is  fervently  hoped  that 
any  one  who  comes  to  a  better  knowledge  of  God's 
works  through  reading  this  book,  may  thereby  come  to 
a  more  intimate  knowledge  of  the  Worker. 

I  take  great  pleasure  in  acknowledging  my  indebted- 
ness to  J.  M.  Van  Yleck,  LL.D.,  of  the  U.  S.  Nautical 
Almanac  staff,  and  Professor  of  Astronomy  at  the  Wes- 
leyan  University,  for  inspecting  some  of  the  more  im- 
portant chapters ;  to  Dr.  S.  S.  White,  of  Philadelphia, 
for  telescopic  advantages ;  to  Professor  Henry  Draper, 
for  furnishing,  in  advance  of  publication,  a  photograph 
of  the  sun's  corona  in  1878 ;  and  to  the  excellent  work 
on  "Popular  Astronomy,"  by  Professor  Simon  New- 
comb,  LL.D.,  Professor  U.  S.  Naval  Observatory,  for 
some  of  the  most  recent  information,  and  for  the  use  of 
the  unequalled  engravings  of  Jupiter,  Saturn,  and  the 
great  nebula  of  Orion. 


THE    CONSTELLATIONS 


ORION    AND    TAURUS, 


NOTES.— Star  a  in  Taurus  is  red,  has  eight  metals ;  moves  east  (page  22T).  At  o 
above  tip  of  right  horn  is  the  Crab  Nebula  (page  219).  In  Orion,  a  is  variable, 
hao  five  metals ;  recedes  22  miles  per  second.  /3,  3,  e,  f ,  p,  etc.,  are  double  stars, 
the  component  parts  of  various  colors  and  magnitudes  (page  212,  note).  X  and  « 
are  triple ;  <r,  octuple;  0,  multiple,  surrounded  by  a  fine  Nebula  (page  218). 


RECREATIONS  IN  ASTRONOMY 


WITH 

DIRECTIONS  FOR  PRACTICAL  EXPERIMENTS 
AND   TELESCOPIC  WORK 


BY 


HEXRY  WHITE  WARREK,  D.D. 

AUTHOR  OF  "SIGHTS  AND  INSIGHTS;   OR,  KNOWLEDGE  BY  TRAVEL,"  ETC. 


WITH   EIGHTY-THREE   ILLUSTRATIONS  AND   MAPS  OF   STARS 


NEW    YORK 

HARPER  &  BROTHERS,  PUBLISHERS 

FRANKLIN  SQUARE 


Entered  according  to  Act  of  Congress,  in  the  year  1879,  by 

HARPER    &    BROTHERS, 
In  the  Office  of  the  Librarian  of  Congress,  at  Washington, 


CONTENTS. 


CHAP.  PAGE 

I.  CREATIVE  PROCESSES 1 

II.  CREATIVE  PROGRESS 15 

Constitution  of  Light 24 

Chemistry  of  Suns  revealed  by  Light 28 

Creative  Force  of  Light 30 

III.  ASTRONOMICAL  INSTRUMENTS 41 

The  Telescope 43 

The  Reflecting  Telescope 44 

The  Spectroscope 46 

IV.  CELESTIAL  MEASUREMENTS 55 

Celestial  Movements 58 

How  to  Measure 60 

V.  THE  SUN 75 

What  the  Sun  does  for  us 94 

VI.  THE  PLANETS,  AS  SEEN  FROM  SPACE 97 

The  Outlook  from  the  Earth 108 

VII.  SHOOTING-STARS,  METEORS,  AND  COMETS 117 

Aerolites 122 

Comets 126 

Famous  Comets 128 

Of  what  do  Comets  consist? 131 

Will  Comets  strike  the  Earth  ? 133 

VIII.  THE  PLANETS  AS  INDIVIDUALS 135 

Vulcan 138 

Mercury 138 

Venus 139 

The  Earth 141 

The  Aurora  Borealis 143 


CONTENTS. 


CHAP. 

VIII.  THE  PLANETS  AS  INDIVIDUALS—  Continued. 

The  Delicate  Balance  of  Forces  ...................................  144 

Tides  .....................................................................  146 

The  Moon  ...............................................................  151 

Telescopic  Appearance  ...............................................  155 

Eclipses  ..................................................................  157 

Mars  ......................................................................   159 

Satellites  of  Mars  ......................................................  161 

Asteroids  ................................................................  162 

Jupiter  ...................  ................................................  164 

Satellites  of  Jupiter  ...................................................  165 

Saturn  ....................................................................  167 

Rings  of  Saturn  ........................................................  169 

Satellites  of  Saturn  ....................................................  172 

Uranus.  ..................................................................  173 

Neptune  .................................................................  175 

IX.  THE  NEBULAR  HYPOTHESIS  ..........................................  179 

X.  THE  STELLAR  SYSTEM  .................................................  193 

The  Open  Page  of  the  Heavens  ....................................  195 

Equatorial  Constellations  ............................................  202 

Characteristics  of  the  Stars  ..........................................  209 

Number  ..................................................................  210 

Double  and  Multiple  Stars  ..........................................  210 

Colored  Stars  ...........................................................  214 

Clusters  of  Stars  ........  ,  ..............................................  215 

Nebulae  ...................................................................  217 

Variable  Stars  .........................................................  220 

Temporary,  New,  and  Lost  Stars  ..................................  223 

Movements  of  Stars  ...................................................  226 

XI.  THE  WORLDS  AND  THE  WORD  .....................................  229 

XII.  THE  ULTIMATE  FORCE  ................................................  247 

SUMMARY  OF  LATEST  DISCOVERIES  AND  CONCLUSIONS  ...............  268 

SOME  ELEMENTS  or  THE  SOLAR  SYSTEM  .................................  274 

EXPLANATION  OF  ASTRONOMICAL  SYMBOLS  ...............................  275 

Signs  of  the  Zodiac  ...................................................  275 

Other  Abbreviations  Used  in  the  Almanac  .....  .................  275 

Greek  Alphabet  Used  Indicating  the  Stars  ......................  275 

CHAUTAUQUA  OUTLINE  FOK  STUDENTS  .....................................  276 

GLOSSARY  OF  ASTRONOMICAL  TERMS  AND  INDEX  ..............  ,  .......  279 


ILLUSTRATIONS. 


FIG.  PAGE 

The  Constellations  of  Orion  and  Taurus Frontispiece 

1.  An  Orbit  resulting  from  Attraction  and  Projection 8 

2.  The  Moon's  Orbit  about  the  Earth 10 

3.  Changes  of  Orbit  by  Mutual  Attraction 11 

4.  Velocity  of  Light  measured  by  Jupiter's  Satellites 22 

5.  Velocity  of  Light  measured  by  Fizeau's  Toothed  Wheel 23 

6.  White  Light  resolved  into  Colors 25 

7.  Showing  amount  of  Light  received  by  Different  Planets 37 

8.  Measuring  Intensities  of  Lights 37 

9.  Reflection  and  Diffusion  of  Light 38 

10.  Manifold  Reflections 39 

11.  Refraction  by  Water 40 

12.  Atmospherical  Refraction 40 

13.  Refracting  Telescope 43 

14.  Reflecting  Telescope 44 

15.  The  Cambridge  Equatorial  Refractor 46 

16.  The  new  Reflecting  Telescope  at  Paris 47 

17.  Spectroscope,  with  Battery  of  Prisms 49 

18.  Spectra  of  Glowing  Hydrogen  and  of  the  Sun 50 

19.  Illustrating  Arcs  and  Angles 59 

20.  Measuring  Objects  by  observing  Angles ."»9 

21.  Mural  Circle 61 

22.  Scale  to  measure  Hundredths  of  an  Inch 63 

23.  Spider-lines  to  determine  Star  Transits 65 

24.  Illustrating  Triangulation 66 


xii  ILLUSTRATIONS. 

FIG.  PAGE 

25.  Measuring  Distance  to  an  Inaccessible  Object 67 

26.  Measuring  Elevation  of  an  Inaccessible  Object 67 

27.  Illustrating  Parallax 69 

28.  Illustrating  Stellar  Parallax 71 

29.  Mode  of  Ascertaining  Longitude 72 

30.  Relative  Size  of  Sun,  as  seen  from  Different  Planets 79 

31.  Zodiacal  Light 80 

32.  Corona  of  the  Sun  in  1858— Brazil 82 

33.  Corona  of  the  Sun  in  1878— Colorado 83 

34.  Solar  Prominences  of  Flaming  Hydrogen 85 

35.  Changes  in  Solar  Cavities  during  Rotation 90 

36.  Solar  Spot 92 

37.  Holding  Telescope  to  see  the  Sun-spots 96 

38.  Orbits  and  Comparative  Sizes  of  the  Planets 100 

39.  Orbit  of  Earth,  illustrating  Seasons 103 

40.  Inclination  of  Planes  of  Planetary  Orbits 107 

41.  Inclination  of  Orbits  of  Earth  and  Venus 107 

42.  Showing  the  Sun's  Movement  among  the  Stars 110 

43.  Passage  of  the  Sun  by  Star  Regulus Ill 

44.  Apparent  Path  of  Jupiter  among  the  Stars 112 

45.  Illustrating  Position  of  Planets 112 

46.  Apparent  Movements  of  an  Inferior  Planet. 113 

47.  Apparent  Movements  of  a  Superior  Planet 114 

47a.  A  Swarm  of  Meteors  meeting  the  Earth 118 

48.  Explosion  of  a  Bolide 120 

49.  Flight  of  Bolides 121 

50.  The  Santa  Rosa  Aerolite 122 

51.  Orbit  of  November  Meteors  and  the  Comet  of  1866 125 

52.  Aspects  of  Remarkable  Comets 127 

53.  Phases  and  Apparent  Dimensions  of  Venus 140 

54.  The  Earth  and  Moon  in  Space 142 

55.  Aurora  as  Waving  Curtains 143 

56.  Tide  resulting  from  Centrifugal  Motion 147 

57.  Lunar  Landscape , 150 


ILLUSTRATIONS.  xiii 

FIG.  PAGE 

58.  Telescopic  View  of  the  Moon 154 

59.  Illumination  of  Lunar  Craters  and  Peaks 155 

60.  Lunar  Crater  "Copernicus" 156 

61.  Eclipses:  Shadows  of  Earth  and  Moon 157 

62.  Apparent  Sizes  of  Mars,  seen  from  the  Earth 160 

63.  Jupiter 164 

64.  Various  Positions  of  Jupiter's  Satellites 166 

65.  View  of  Saturn  and  his  Rings 168 

66.  Perturbations  of  Uranus 176 

67.  Map:  Circumpolar  Constellations 201 

68.  Map  of  Constellations  on  the  Meridian  in  December 202 

.69.  Map  of  Constellations  on  the  Meridian  in  January 203 

70.  Map  of  Constellations  on  the  Meridian  in  April 204 

71.  Map  of  Constellations  on  the  Meridian  in  June 205 

72.  Map  of  Constellations  on  the  Meridian  in  September.... 206 

73.  Map  of  Constellations  on  the  Meridian  in  November. 207 

74.  Southern  Circumpolar  Constellations 208 

75.  Aspects  of  Double  Stars 213 

76.  Sprayed  Star  Cluster  below  i\  in  Hercules 216 

77.  Globular  Star  Cluster  in  the  Centaur 216 

78.  Great  Nebula  about  6  Orionis 218 

79.  The  Crab  Nebula  above  £  Tauri 219 

80.  The  Ring  Nebula  in  Lyra 220 

81.  Showing  Place  of  Ring  Nebula 221 

82.  The  Horizontal  Pendulum ..  272 


COLORED  PLATE  REPRESENTING  VARIOUS  SPECTRA 50-52 

MAPS  TO  FIND  THE  STARS ..  At  the  End. 


I. 

CREATIVE   PROCESSES. 

"  In  the  beginning  God  created  the  heaven  and  the  earth.  And  the 
earth  was  without  form,  and  void ;  and  darkness  was  upon  the  face  of  the 
deep." — Genesis  i.  1,2. 

1 


"Not  to  the  domes,  where  crumbling  arch  and  column 

Attest  the  feebleness  of  mortal  hand, 
But  to  that  fane,  most  catholic  and  solemn, 

Which  God  hath  planned, — 
To  that  cathedral,  boundless  as  our  wonder, 

Whose  quenchless  lamps  the  sun  and  moon  supply  , 
Its  chdr  the  winds  and  waves,  its  organ  thunder, 

Its  dome  the  sky."  HOHACK  SMITH. 

'  The  heavens  are  a  point  from  the  pen  of  His  perfection  ; 
The  world  is  a  rose-bud  from  the  bower  of  His  beauty ; 
The  sun  is  a  spark  from  the  light  of  His  wisdom  ; 
And  the  sky  a  bubble  on  the  sea  of  His  power." 

SIR  W.  JOXES. 


RECREATIONS  IN  ASTRONOMY. 


I. 

CREATIVE  PROCESSES. 

DURING  all  the  ages  there  has  been  one  bright  and 
glittering  page  of  loftiest  wisdom  unrolled  before  the 
eye  of  man.  That  this  page  may  be  read  in  every  part, 
man's  whole  world  turns  him  before  it.  This  motion 
apparently  changes  the  eternally  stable  stars  into  a  mov- 
ing panorama,  but  it  is  only  so  in  appearance.  The 
sky  is  a  vast,  immovable  dial-plate  of  "  that  clock  whose 
pendulum  ticks  ages  instead  of  seconds,"  and  whose 
time  is  eternity.  The  moon  moves  among  the  illumi- 
nated figures,  traversing  the  dial  quickly,  like  a  second- 
hand, once  a  month.  The  sun,  like  a  minute-hand,  goes 
over  the  dial  once  a  year.  Various  planets  stand  for 
hour-hands,  moving  over  the  dial  in  various  periods 
reaching  up  to  one  hundred  and  sixty-four  years ;  while 
the  earth,  like  a  ship  of  exploration,  sails  the  infinite 
azure,  bearing  the  observers  to  different  points  where 
they  may  investigate  the  infinite  problems  of  this 
mighty  machinery. 

This  dial  not  only  shows  present  movements,  but  it 
keeps  the  history  of  uncounted  ages  past  ready  to  be 


4  CREATIVE  PROCESSES. 

read  backward  in  proper  order ;  and  it  has  glorious  vol- 
umes of  prophecy,  revealing  the  far-off  future  to  any 
man  who  is  able  to  look  thereon,  break  the  seals,  and 
read  the  record.  Glowing  stars  are  the  alphabet  of 
this  lofty  page.  They  combine  to  form  words.  Mete- 
ors, rainbows,  auroras,  shifting  groups  of  stars,  make 
pictures  vast  and  significant  as  the  armies,  angels,  and 
falling  stars  in  the  Revelation  of  St.  John — changing 
and  progressive  pictures  of  infinite  wisdom  and  power. 

Men  have  not  yet  advanced  as  far  as  those  who  saw 
the  pictures  John  describes,  and  hence  the  panorama  is 
not  understood.  That  continuous  speech  that  day  af- 
ter day  uttereth  is  not  heard ;  the  knowledge  that  night 
after  night  showeth  is  not  seen ;  and  the  invisible 
things  of  God  from  the  creation  of  the  world,  even  his 
eternal  power  and  Godhead,  clearly  discoverable  from 
things  that  are  made,  are  not  apprehended. 

The  greatest  triumphs  of  men's  minds  have  been  in 
astronomy — and  ever  must  be.  We  have  not  learned 
its  alphabet  yet.  We  read  only  easy  lessons,  with  as 
many  mistakes  as -happy  guesses.  But  in  time  we  shall 
know  all  the  letters,  become  familiar  with  the  combi- 
nations, be  apt  at  their  interpretation,  and  will  read 
with  facility  the  lessons  of  wisdom  and  power  that  are 
written  on  the  earth,  blazoned  in  the  skies,  and  pictured 
by  the  flowers  below  and  the  rainbows  above. 

In  order  to  know  how  worlds  move  and  develop,  we 
must  create  them ;  we  must  go  back  to  their  begin- 
ning, give  their  endowment  of  forces,  and  study  the 
laws  of  their  unfolding.  This  we  can  easily  do  by  that 
faculty  wherein  man  is  likest  his  Father,  a  creative  im- 
agination. God  creates  and  embodies;  we  create,  but 


FORCE  OF  ATTRACTION.  5 

it  remains  in  thought  only.  But  the  creation  is  as 
bright,  strong,  clear,  enduring,  and  real,  as  if  it  were  em- 
bodied. E\7ery  one  of  us  would  make  worlds  enough 
to  crush  us,  if  we  could  embody  as  well  as  create.  Our 
ambition  would  outrun  our  wisdom.  Let  us  come  into 
the  high  and  ecstatic  frame  of  mind  which  Shakspeare 
calls  frenzy,  in  the  exigencies  of  his  verse,  when 

"The  poet's  eye,  in  a  fine  frenzy  rolling, 
Doth  glance  from  heaven  to  earth,  from  earth  to  heaven  ; 
And,  as  imagination  bodies  forth 
The  forms  of  things  unknown,  the  poet's  pen 
Turns  them  to  shapes,  and  gives  to  airy  nothing 
A  local  habitation  and  a  name." 

la  the  supremacy  of  our  creative  imagination  let  us 
make  empty  space,  in  order  that  we  may  therein  build 
up  a  new  universe.  Let  us  wave  the  wand  of  our  pow- 
er, so  that  all  created  things  disappear.  There  is  no 
world  under  our  feet,  no  radiant  clouds,  no  blazing  sun, 
no  silver  moon,  nor  twinkling  stars.  We  look  up,  there 
is  no  light ;  down,  through  immeasurable  abysses,  there 
is  no  form;  all  about,  and  there  is  no  sound  or  sign 
of  being — nothing  save  utter  silence,  utter  darkness.  It 
cannot  be  endured.  Creation  is  a  necessity  of  mind — 
even  of  the  Divine  mind. 

We  will  now,  by  imagination,  create  a  monster  world, 
every  atom  of  which  shall  be  dowered  with  the  single 
power  of  attraction.  Every  particle  shall  reach  out 
its  friendly  hand,  and  there  shall  be  a  drawing  to- 
gether of  every  particle  in  existence.  The  laws  gov- 
erning this  attraction  shall  be  two.  When  these  parti- 
cles are  associated  together,  the  attraction  shall  be  in 
proportion  to  the  mass.  A  given  mass  will  pull  twice 


G  CREATIVE  PROCESSES. 

as  much  as  one  of  half  the  size,  because  there  is  twice 
as  much  to  pull.  And  a  given  mass  will  be  pulled 
twice  as  much  as  one  half  as  large,  because  there  is 
twice  as  much  to  be  pulled.  A  man  who  weighed  one 
hundred  and  fifty  pounds  on  the  earth  might  weigh  a 
ton  and  a  half  on  a  body  as  large  as  the  sun.  That 
shall  be  one  law  of  attraction;  and  the  other  shall  be 
that  masses  attract  inversely  as  the  square  of  distances 
between  them.  Absence  shall  affect  friendships  that 
have  a  material  basis.  If  a  body  like  the  earth  pulls  a 
man  one  hundred  and  fifty  pounds  at  the  surface,  or 
four  thousand  miles  from  the  centre,  it  will  pull  the 
same  man  one -fourth  as  much  at  twice  the  distance, 
one-sixteenth  as  much  at  four  times  the  distance.  That 
is,  he  will  weigh  by  a  spring  balance  thirty-seven  and  a 
half  pounds  at  eight  thousand  miles  from  the  centre, 
and  nine  pounds  six  ounces  at  sixteen  thousand  miles 
from  the  centre,  and  he  will  weigh  or  be  pulled  by  the 
earth  ¥V  of  a  pound  at  the  distance  of  the  moon.  But 
the  moon  would  be  large  enough  and  near  enough  to 
pull  twenty-four  pounds  on  the  same  man,  so  the  earth 
could  not  draw  him  away.  Thus  the  two  laws  of  at- 
traction of  gravitation  are — 1,  Gravity  is  proportioned 
to  the  quantity  of  matter  ;  and  2,  The  force  of  gravity 
varies  inversely  as  the  square  of  the  distance  from  the 
centre  of  the  attracting  l)ody. 

The  original  form  of  matter  is  gas.  Almost  as  I 
write  comes  the  announcement  that  Mr.  Lockyer  has 
proved  that  all  the  so-called  primary  elements  of  mat- 
ter are  only  so  many  different  sized  molecules  of  one 
original  substance  —  hydrogen.  Whether  that  is  true 
or  not,  let  us  now  create  all  the  hydrogen  we  can 


FORCE  OF  ATTRACTION.  7 

imagine,  either  in  differently  sized  masses  or  in  com- 
bination with  other  substances.  There  it  is !  We  can- 
not measure  its  bulk ;  we  cannot  fly  around  it  in  any 
recordable  eons  of  time.  It  has  boundaries,  to  be  sure, 
for  we  are  finite,  but  we  cannot  measure  them.  Let  it 
alone,  now ;  leave  it  to  itself.  What  follows  ?  It  is 
dowered  simply  with  attraction.  The  vast  mass  begins 
to  shrink,  the  outer  portions  are  drawn  inward.  They 
rush  and  swirl  in  vast  cyclones,  thousands  of  miles  in 
extent.  The  centre  grows  compact,  heat  is  evolved  by 
impact,  as  will  be  explained  in  Chapter  II.  Dull  red 
light  begins  to  look  like  coming  dawn.  Centuries  go 
by ;  contraction  goes  on ;  light  blazes  in  insufferable 
brightness ;  tornadoes,  whirlpools,  and  tempests  scarcely 
signify  anything  as  applied  to  such  tumultuous  tossing. 

There  hangs  the  only  world  in  existence ;  it  hangs  in 
empty  space.  It  has  no  tendency  to  rise ;  none  to  fall ; 
none  to  move  at  all  in  any  direction.  It  seethes  and 
flames,  and  holds  itself  together  by  attractive  power,  and 
that  is  all  the  force  with  which  we  have  endowed  it. 

Leave  it  there  alone,  and  withdraw  millions  of  miles 
into  space:  it  looks  smaller  and  smaller.  We  lose  sight 
of  those  distinctive  spires  of  flame,  those  terrible  move- 
ments. It  only  gives  an  even  effulgence,  a  steady  un- 
flickering  light.  Turn  one  quarter  round.  Still  we  see 
our  world,  but  it  is  at  one  side. 

Now  in  front,  in  the  utter  darkness,  suddenly  create 
another  world  of  the  same  size,  and  at  the  same  distance 
from  you.  There  they  stand — two  huge,  lone  bodies,  in 
£mpty  space.  But  we  created  them  dowered  with  at- 
traction. Each  instantly  feels  the  drawing  influence  of 
the  other.  They  are  mutually  attractive,  and  begin  to 


8  CREATIVE  PROCESSES. 

move  toward  each  other.  They  hasten  along  an  uncle- 
viating  straight  line.  Their  speed  quickens  at  every 
mile.  The  attraction  increases  every  moment.  They 
fly  swift  as  thought.  They  clash  their  flaming,  seething 
foreheads  together. 

And  now  we  have  one  world  again.  It  is  twice  as 
large  as  before,  that  is  all  the  difference.  There  is  no 
variety,  neither  any  motion  ;  just  simple  flame,  and  noth- 
ing to  be  warmed  thereby.  Are  our  creative  powers 
exhausted  by  this  effort  ? 

No,  we  will  create  another  world,  and  add  another 
power  to  it  that  shall  keep  them  apart.  That  power 


D 

Fig.  1.— Orbit  A  D,  resultiug  from  attraction,  A  C,  and  projectile  force,  A  B. 

shall  be  what  is  called  the  force  of  inertia,  which  is 
literally  no  power  at  all ;  it  is  an  inability  to  originate 
or  change  motion.  If  a  body  is  at  rest,  inertia  is  that 
quality  by  which  it  will  forever  remain  so,  unless  acted 
upon  by  some  force  from  without ;  and  if  a  body  is  in 
motion,  it  will  continue  on  at  the  same  speed,  in  a 
straight  line,  forever,  unless  it  is  quickened,  retarded, 
or  turned  from  its  path  by  some  other  force.  Suppose 
our  newly  created  sun  is  860,000  miles  in  diameter.  Go 
away  92,500,000  miles  and  create  an  earth  eight  thou- 
sand miles  in  diameter.  It  instantly  feels  the  at- 
tractive power  of  the  sun  drawing  it  to  itself  twenty- 


FORCES  OF  ATTRACTION  AND  INERTIA.  9 

four  miles  the  first  hour.  Now,  just  as  it  starts,  give 
this  earth  a  push  in  a  line  at  right  angles  with  line  of 
fall  to  the  sun,  that  shall  send  it  66,168  miles  every 
hour  thereafter.  It  obeys  both  forces.  The  result  is 
that  the  world  moves  constantly  forward  at  the  same 
speed  by  its  inertia  from  that  first  push,  and  attraction 
momentarily  draws  it  from  its  straight  line,  so  that  the 
new  world  circles  round  the  other  to  the  starting-point. 
Continuing  under  the  operation  of  both  forces,  the 
worlds  can  never  come  together  or  fly  apart. 

They  circle  about  each  other  as  long  as  these  forces 
endure ;  for  the  first  world  does  not  stand  still  and 
the  second  do  all  the  going ;  both  revolve  around  the 
centre  of  gravity  common  to  both.  In  case  the  worlds 
are  equal  in  mass,  they  will  both  take  the  same  orbit 
around  a  central  stationary  point,  midway  between  the 
two.  In  case  their  mass  be  as  one  to  eighty-one,  as  in 
the  case  of  the  earth  and  the  moon,  the  centre  of  grav- 
ity around  which  both  turn  will  be  -gV  of  the  distance 
from  the  earth's  centre  to  the  moon's  centre.  This 
brings  the  central  point  around  which  both  worlds 
swing  just  inside  the  surface  of  the  earth.  It  is  like 
an  apple  attached  by  a  string,  and  swung  around  the 
hand  ;  the  hand  moves  a  little,  the  apple  very  much. 

Thus  the  problem  of  two  revolving  bodies  is  readily 
comprehended.  The  two  bodies  lie  in  easy  beds,  and 
swing  obedient  to  constant  forces.  "When  another  body, 
however,  is  introduced,  with  its  varying  attraction,  first 
on  one  and  then  on  the  other,  complications  are  intro- 
duced that  only  the  most  masterly  minds  can  follow. 
Introduce  a  dozen  or  a  million  bodies,  and  complica- 
tions arise  that  only  Omniscience  can  unravel. 

1* 


10  CREATIVE  PROCESSES. 

Let  the  hand  swing  an  apple  by  an  elastic  cord. 
When  the  apple  falls  toward  the  earth  it  feels  another 
force  besides  that  derived  from  the  hand,  which  greatly 
lengthens  the  elastic  cord.  To  tear  it  away  from  the 
earth's  attraction,  and  make  it  rise,  requires  additional 
force,  and  hence  the  string  is  lengthened ;  but  when  it 
passes  over  the  hand  the  earth  attracts  it  downward, 
and  the  string  is  very  much  shortened :  so  the  moon, 
held  by  an  elastic  cord,  swings  around  the  earth.  From 
its  extreme  distance  from  the  earth,  at  A,  Fig.  2,  it 
rushes  with  increasing  speed  nearly  a 

O     quarter  of  a  million  of  miles  toward 
c   the  sun,  feeling  its  attraction  increase 
with  every  mile  until  it  reaches  B; 
then  it  is  retarded  in  its  speed,  by  the 
same  attraction,  as  it  climbs  back  its 
quarter   of  a  million  of  miles  away 
from  the  sun,  in  defiance  of  its  pow- 
er, to  C.     All  the  while  the  invisi- 
ble elastic  force  of  the  earth  is  un- 
weariedly  maintained ;    and  though   the   moon's   dis- 
tances vary  over  a  range  of  31,355  miles,  the  moon 
is  always  in  a  determinable  place.     A  simple  revolu- 
tion of  one  world  about  another  in  a  circular  orbit 
would  be  a  problem  of  easy  solution.     It  would  always 
be  at  the  same  distance  from  its  centre,  and  going  with 
the  same  velocity.    But  there  are  over  sixty  causes  that 
interfere  with  such  a  simple  orbit  in  the  case  of  the 
moon,  all  of  which  causes  and  their  disturbances  must 
be  considered  in  calculating  such  a  simple  matter  as  an 
eclipse,  or  predicting  the  moon's  place  as  the  sailors' 
guide.     One  of  the  most  puzzling  of  the  irregularities 


FORCES  OF  ATTRACTION  AND  INERTIA.  11 

of  our  night-wandering  orb  has  just  been  explained  by 
Professor  Hansen,  of  Gotha,  as  a  curious  result  of  the 
attraction  of  Venus. 

Take  a  single  instance  of  the  perturbations  of  Jupiter 
and  Saturn  which  can  be  rendered  evident.  The  times 
of  orbital  revolution  of  Saturn  and  Jupiter  are  nearly  as 
five  to  two.  Suppose  the  orbits 
of  the  planets  to  be,  as  in  Fig.  3, 
both  ellipses,  but  not  necessarily 
equally  distant  in  all  parts.  The 
planets  are  as  near  as  possible 
at  1,1.  Drawn  toward  each  oth- 
er by  mutual  attraction,  Jupi- 
ter's orbit  bends  outward,  and  Fig.3._c^f^f  orbit  by 
Saturn's  becomes  more  nearly  mutual  attraction, 
straight,  as  shown  by  the  dotted  lines.  A  partial  cor- 
rection of  this  difficulty  immediately  follows.  As  Jupi- 
ter moves  on  ahead  of  Saturn  it  is  held  back — retarded 
in  its  orbit  by  that  body ;  and  Saturn  is  hastened  in  its 
orbit  by  the  attraction  of  Jupiter.  Now  greater  speed 
means  a  straighter  orbit.  A  rifle-ball  flies  nearer  in  a 
straight  line  than  a  thrown  stone.  A  greater  velocity 
given  to  a  whirled  ball  pulls  the  elastic  cord  far  enough 
to  give  the  ball  a  larger  orbit.  Hence,  being  hastened, 
Saturn  stretches  out  nearer  its  proper  orbit,  and,  retard- 
ed, Jupiter  approaches  the  smaller  curve  that  is  its  true 
orbit. 

But  if  they  were  always  to  meet  at  this  point,  as  they 
would  if  Jupiter  made  two  revolutions  to  Saturn's  one, 
it  would  be  disastrous.  In  reality,  when  Saturn  has 
gone  around  two-thirds  of  its  orbit  to  2,  Jupiter  will 
have  gone  once  and  two-thirds  around  and  overtaken 


12  CREATIVE  PROCESSES. 

Saturn ;  and  they  will  be  near  again,  be  drawn  togeth- 
er, hastened,  and  retarded,  as  before ;  their  next  con- 
junction would  be  at  3,  3,  etc. 

Now,  if  they  always  made  their  conjunction  at  points 
equally  distant,  or  at  thirds  of  their  orbits,  it  would  cause 
a  series  of  increasing  deviations;  for  Jupiter  would 
be  constantly  swelling  his  orbit  at  three  points,  and 
Saturn  increasingly  contracting  his  orbit  at  the  same 
points.  Disaster  would  be  easily  foretold.  But  as  their 
times  of  orbital  revolutions  are  not  exactly  in  the  ratio 
of  five  and  two,  their  points  of  conjunction  slowly  travel 
around  the  orbit,  till,  in  a  period  of  nine  hundred  years, 
the  starting-point  is  again  reached,  and  the  perturba- 
tions have  mutually  corrected  one  another. 

For  example,  the  total  attractive  effect  of  one  planet 
on  the  other  for  450  years  is  to  quicken  its  speed.  The 
effect  for  the  next  450  years  is  to  retard.  The  place  of 
Saturn,  when  all  the  retardations  have  accumulated  for 
450  years,  is  one  degree  behind  what  it  is  computed  if 
they  are  not  considered ;  and  450  years  later  it  wrill  be 
one  degree  before  its  computed  place — a  perturbation 
of  two  degrees.  When  a  bullet  is  a  little  heavier  or 
ragged  on  one  side,  it  will  constantly  swerve  in  that  di- 
rection. The  spiral  groove  in  the  rifle,  of  one  turn  in 
forty-five  feet,  turns  the  disturbing  weight  or  raggedness 
from  side  to  side — makes  one  error  correct  another,  and 
so  the  ball  flies  straight  to  the  bull's-eye.  So  the  place  of 
Jupiter  and  Saturn,  though  further  complicated  by  four 
moons  in  the  case  of  Jupiter,  and  eight  in  the  case  of 
Saturn,  and  also  by  perturbations  caused  by  other  plan- 
ets, can  be  calculated  with  exceeding  nicety. 

The  difficulties  would  be  greatly  increased  if  the  or* 


FORCES  OF  ATTRACTION  AND  INERTIA.          13 

bits  of  Saturn  and  Jupiter,  instead  of  being  400,000,000 
miles  apart,  were  interlaced.  Yet  there  are  the  orbits 
of  one  hundred  and  ninety-two  asteroids  so  interlaced 
that,  if  they  were  made  of  wire,  no  one  could  be  lifted 
without  raising  the  whole  net-work  of  them.  Never- 
theless, all  these  swift  chariots  of  the  sky  race  along  the 
course  of  their  intermingling  tracks  as  securely  as  if 
they  were  each  guided  by  an  intelligent  mind.  They 
are  guided  Try  an  intelligent  tnind  and  an  almighty 
arm. 

Still  more  complicated  is  the  question  of  the  mutual 
attractions  of  all  the  planets.  Lagrange  has  been  able 
to  show,  by  a  mathematical  genius  that  seems  little  short 
of  omniscience  in  his  single  department  of  knowledge, 
that  there  is  a  discovered  system  of  oscillations,  affect- 
ing the  entire  planetary  system,  the  periods  of  which 
are  immensely  long.  The  number  of  these  oscillations 
is  equal  to  that  of  all  the  planets,  arid  their  periods 
range  from  50,000  to  2,000,000  years. 

Looking  into  the  open  page  of  the  starry  heavens  wo 
see  double  stars,  the  constituent  parts  of  which  must  re- 
volve around  a  centre  common  to  them  both,  or  rush  to 
a  common  ruin.  Eagerly  we  look  to  see  if  they  revolve, 
and  beholding  them  in  the.  very  act,  we  conclude,  not 
groundlessly,  that  the  same  great  law  of  gravitation 
holds  good  in  distant  stellar  spaces,  and  that  there  the 
same  sufficient  mind  plans,  and  the  same  sufficient 
power  directs  and  controls  all  movements  in  harmony 
and  security. 

When  we  come  to  the  perturbations  caused  by  the 
mutual  attractions  of  the  sun,  nine  planets,  twenty 
moons,  one  hundred  and  ninety-two  asteroids,  millions 


14:  CREATIVE  PROCESSES. 

of  comets,  and  innumerable  meteoric  bodies  swarming 
in  space,  and  when  we  add  to  all  these,  that  belong  to 
one  solar  system,  the  attractions  of  all  the  systems  of 
the  other  suns  that  sparkle  on  a  brilliant  winter  night, 
we  are  compelled  to  say,  "  As  high  as  the  heavens  are 
above  the  earth,  so  high  above  our  thoughts  and  ways 
must  be  the  thoughts  and  ways  of  Him  who  compre- 
hends and  directs  them  all." 


II. 

CREATIVE    PROGRESS, 

"And  God  said,  Let  there  be  light,  and  there  was  light." — Genesis 
i.,  3. 

"  God  is  light."— 1  John,  i.,  5. 


"  Hail!  holy  light,  offspring  of  Heaven  first  born, 
Or  of  the  eternal,  co-eternal  beam, 
May  I  express  thee  unblamed  ?  since  God  is  light, 
And  never  but  in  unapproached  light 
Dwelt  from  eternity,  dwelt  then  in  thee, 
Bright  effluence  of  bright  essence  increate." 

MILTON. 

"  A  million  torches  lighted  by  Thy  hand 
Wander  unwearied  through  the  blue  abyss  : 
They  own  Thy  power,  accomplish  Thy  command, 
All  gay  with  life,  all  eloquent  with  bliss. 
What  shall  we  call  them  ?    Piles  of  crystal  light— 
A  glorious  company  of  golden  streams — 
Lamps  of  celestial  ether  burning  bright — 
Suns  lighting  systems  with  their  joyous  beams  ? 
But  Thou  to  these  art  as  the  noon  to  night." 

DERZHAVIN,  trans,  by  BOWRING, 


FORCES  OF  THE  SUNBEAM.  17 


II. 
CREATIVE  PROGRESS. 

WORLDS  would  be  very  imperfect  and  useless  when 
simply  endowed  with  attraction  and  inertia,  if  no  time 
were  allowed  for  these  forces  to  work  out  their  legiti- 
mate results.  We  want  something  more  than  swirling 
seas  of  attracted  gases,  something  more  than  compacted 
rocks.  We  look  for  soil,  verdure,  a  paradise  of  beauty, 
animal  life,  and  immortal  minds.  Let  us  go  on  with 
the  process. 

Light  is  the  child  of  force,  and  the  child,  like  its  fa- 
ther, is  full  of  power.  We  dowered  our  created  world 
with  but  a  single  quality — a  force  of  attraction.  It  not 
only  had  attraction  for  its  own  material  substance,  but 
sent  out  an  all-pervasive  attraction  into  space.  By  the 
force  of  condensation  it  flamed  like  a  sun,  and  not  only 
lighted  its  own  substance,  but  it  filled  all  space  with 
the  luminous  outgoings  of  its  power.  A  world  may  be 
limited,  but  its  influence  cannot ;  its  body  may  have 
bounds,  but  its  soul  is  infinite.  Everywhere  is  its  mani- 
festation as  real,  power  as  effective,  presence  as  actual, 
as  at  the  central  point.  He  that  studies  ponderable 
bodies  alone  is  not  studying  the  universe,  only  its  skel- 
eton. Skeletons  are  somewhat  interesting  in  themselves, 
but  far  more  so  when  covered  with  flesh,  flushed  with 
beauty,  and  inspired  with  soul.  The  universe  has  bones, 


18  CREATIVE  PROGRESS. 

flesh,  beauty,  soul,  and  all  is  one.  It  can  be  understood 
only  by  a  study  of  all  its  parts,  and  by  tracing  effect  to 
cause. 

But  how  can  condensation  cause  light?  Power  can- 
not be  quiet.  The  mighty  locomotive  trembles  with  its 
own  energy.  A  smitten  piece  of  iron  has  all  its  infini- 
tesimal atoms  set  in  vehement  commotion ;  they  surge 
back  and  forth  among  themselves,  like  the  waves  of  a 
storm-blown  lake.  Heat  is  a  mode  of  motion.  A  heat- 
ed body  commences  a  vigorous  vibration  among  its  par- 
ticles, and  communicates  these  vibrations  to  the  sur- 
rounding air  and  ether.  "When  these  vibrations  reach 
396,000,000,000,000  per  second,  the  human  eye,  fitted 
to  be  affected  by  that  number,  discerns  the  emitted  un- 
dulations, and  the  object  seems  to  glow  with  a  dull  red 
light ;  becoming  hotter,  the  vibrations  increase  in  rapid- 
ity. When  they  reach  765,000,000,000,000  per  second 
the  color  becomes  violet,  and  the  eye  can  observe  them 
no  farther.  Between  these  numbers  are  those  of  differ- 
ent rapidities,  which  affect  the  eye — as  orange,  yellow, 
green,  blue,  indigo,  in  an  almost  infinite  number  of 
shades — according  to  the  sensitiveness  of  the  eye. 

We  now  see  how  our  dark  immensity  of  attractive 
atoms  can  become  luminous.  A  force  of  compression 
results  in  vibrations  within,  communicated  to  the  ether, 
discerned  by  the  eye.  Illustrations  are  numerous.  If 
we  suddenly  push  a  piston  into  a  cylinder  of  brass,  the 
force  produces  heat  enough  to  set  fire  to  an  inflam- 
mable substance  within.  Strike  a  half -inch  cube  of 
iron  a  moderate  blow  and  it  becomes  warm ;  a  sufficient 
blow,  and  its  vibrations  become  quick  enough  to  be  seen 
— it  is  red-hot.  Attach  a  thermometer  to  an  extended 


FORCES  OF  THE  SUNBEAM.  19 

arm  of  a  whirling  wheel ;  drive  it  against  the  air  five 
hundred  feet  per  second,  the  mercury  rises  16°.  The 
earth  goes  98,000  feet  per  second,  or  one  thousand  miles 
a  minute.  If  it  come  to  an  aerolite  or  mass  of  metallic 
rock,  or  even  a  cloudlet  of  gas,  standing  still  in  space, 
its  contact  with  our  air  evolves  600,000°  of  heat.  And 
when  the  meteor  comes  toward  the  world  twenty -six 
miles  a  second,  the  heat  would  become  proportionally 
greater  if  the  meteor  could  abide  it,  and  not  be  con- 
sumed in  fervent  heat.  It  vanishes  almost  as  soon  as 
seen.  If  there  were  meteoric  masses  enough  lying  in 
our  path,  our  sky  would  blaze  with  myriads  of  flashes 
of  light.  Enough  have  been  seen  to  enable  a  person 
to  read  by  them  at  night.  If  a  sufficient  number  were 
present,  we  should  miss  their  individual  flashes  as  they 
blend  their  separate  fires  in  one  sea  of  insufferable 
glory.  The  sun  is  326,800  as  heavy  as  our  planet ;  its 
attraction  proportionally  greater;  the  aerolites  more 
numerous;  and  hence  an  infinite  hail  of  stones,  small 
masses  and  little  worlds,  makes  ceaseless  trails  of  light, 
whose  individuality  is  lost  in  one  dazzling  sea  of  glory? 
On  the  1st  day  of  September,  1859,  two  astronomers, 
independently  of  each  other,  saw  a  sudden  brightening 
on  the  surface  of  the  sun.  Probably  two  large  meteoric 
masses  were  travelling  side  by  side  at  two  or  three  hun- 
dred miles  per  second,  and  striking  the  sun's  atmos- 
phere, suddenly  blazed  into  light  bright  enough  to  be 
seen  on  the  intolerable  light  of  the  photosphere  as  a 
background.  The  earth  responded  to  this  new  cause 
of  brilliance  and  heat  in  the  sun.  Yivid  auroras  ap- 
peared, not  only  at  the  north  and  south  poles,  but  even 
where  such  spectacles  are  seldom  seen.  The  electro- 


20  CREATIVE  PROGRESS. 

magnetic  disturbances  were  more  distinctly  marked. 
"  In  many  places  the  telegraphic  wires  struck  work.  In 
Washington  and  Philadelphia  the  electric  signalmen  re- 
ceived severe  electric  shocks;  at  a  station  in  Norway, 
the  telegraphic  apparatus  was  set  fire  to ;  and  at  Boston 
a  flame  of  tire  followed  the  pen  of  Bain's  electric  tele- 
graph." There  is  the  best  of  reason  for  believing  that 
a  continuous  succession  of  such  bodies  might  have  gono 
far  toward  rendering  the  earth  uncomfortable  as  a  place 
of  residence. 

Of  course,  the  same  result  of  heat  and  light  would 
follow  from  compression,  if  a  body  had  the  power  of 
contraction  in  itself.  We  endowed  every  particle  of  our 
gas,  myriads  of  miles  in  extent,  with  an  attraction  for 
every  other  particle.  It  immediately  compressed  itself 
into  a  light-giving  body,  which  flamed  out  through  the 
interstellar  spaces,  flushing  all  the  celestial  regions  with 
exuberant  light. 

But  heat  exerts  a  repellent  force  among  particles,  and 
soon  an  equilibrium  is  reached,  for  there  comes  a  time 
when  the  contracting  body  can  contract  no  farther.  But 
heat  and  light  radiate  away  into  cold  space,  then  contrac- 
tion goes  on  evolving  more  light,  and  so  the  suns  flame 
on  through  the  millions  of  years  unquenched.  It  is  es- 
timated that  the  contraction  of  our  sun,  from  filling  im- 
mensity of  space  to  its  present  size,  could  not  afford 
heat  enough  to  last  more  than  18,000,000  years,  and 
that  its  contraction  from  its  present  density  (that  of 
a  swamp)  to  such  rock  as  that  of  which  our  earth  is 
composed,  could  supply  heat  enough  for  17,000,000 
years  longer.  But  the  far-seeing  mind  of  man  knows 
a  time  must  come  when  the  present  force  of  attraction 


FORCES  OF  THE  SUNBEAM.  21 

shall  liave  produced  all  the  heat  it  can,  and  a  new  force 
of  attraction  must  be  added,  or  the  sun  itself  will  be- 
come cold  as  a  cinder,  dead  as  a  burned-out  char. 

Since  light  and  heat  are  the  product  of  such  enor- 
mous cosmic  forces,  they  must  partake  of  their  nature, 
and  be  force.  So  they  are.  The  sun  has  long  arms, 
and  they  are  full  of  unconquerable  strength  ninety-two 
millions,  or  any  other  number  of  millions,  of  miles 
away.  All  this  light  and  heat  comes  through  space 
that  is  200°  below  zero,  through  utter  darkness,  and  ap- 
pears only  on  the  earth.  So  the  gas  is  darkness  in  the 
underground  pipes,  but  light  at  the  burner.  So  the 
electric  power  is  unfelt  by  the  cable  in  the  bosom  of  the 
deep,  but  is  expressive  of  thought  and  feeling  at  the 
end.  Having  found  the  cause  of  light,  we  will  com- 
mence a  study  of  its  qualities  and  powers. 

Light  is  the  astronomer's  necessity.  "When  the  sub- 
lime word  was  uttered,  "  Let  there  be  light !"  the  study 
of  astronomy  was  made  possible.  Man  can  gather  but 
little  of  it  with  his  eye ;  so  he  takes  a  lens  twenty-six 
inches  in  diameter,  and  bends  all  the  light  that  passes 
through  it  to  a  focus,  then  magnifies  the  image  and 
takes  it  into  his  eye.  Or  he  takes  a  mirror,  six  feet  in 
diameter,  so  hollowed  in  the  middle  as  to  reflect  all  the 
rays  falling  upon  it  to  one  point,  and  makes  this  larger 
eye  fill  his  own  with  light.  By  this  larger  light-gath- 
ering he  discerns  things  for  which  the  light  falling 
on  his  pupil  one-fifth  of  an  inch  in  diameter  would  not 
be  sufficient.  We  never  have  seen  any  sun  or  stars; 
we  have  only  seen  the  light  that  left-  them  a  few  min- 
utes or  years  ago,  more  or  less.  Light  is  the  aerial 
sprite  that  carries  our  measuring-rods  across  the  infinite 


22  CREATIVE  PROGRESS. 

spaces ;  light  spreads  out  the  history  of  that  far-off  be- 
ginning ;  brings  us  the  measure  of  stars  a  thousand  times 
brighter  than  our  sun  ;  takes  up  into  itself  evidences  of 
the  very  constitutional  elements  of  the  far-off  suns,  and 
spreads  them  at  our  feet.  It  is  of  such  capacity  that 
the  Divine  nature,  looking  for  an  expression  of  its  own 
omnipotence,  omniscience,  and  power  of  revelation,  was 
content  to  say,  "  God  is  Light."  We  shall  need  all  our 
delicacy  of  analysis  and  measurement  when  we  seek  to 
determine  the  activities  of  matter  so  fine  and  near  to 
spirit  as  light. 

We  first  seek  the  velocity  of  light.  In  Fig.  4  the 
earth  is  92,500,000  miles  from  the  sun  at  E;  Jupiter 
is  480,000,000  miles  from  the  sun  at  J.  It  has  four 


Fig.  4.— Velocity  of  Light  measured  by  Eclipses  of  Jupiter's  Moons. 

moons :  the  inner  one  goes  around  the  central  body 
in  forty-two  hours,  and  is  eclipsed  at  every  revolution. 
The  light  that  went  out  from  the  sun  to  M  ceases  to  be 
reflected  back  to  the  earth  by  the  intervention  of  the  plan- 
et Jupiter.  We  know  to  a  second  when  these  eclipses 
take  place,  and  they  can  be  seen  witli  a  small  telescope. 
But  when  the  earth  is  on  the  opposite  side  of  the  sun 


FORCES  OF  THE  SUNBEAM. 


23 


from  Jupiter,  at  E',  these  eclipses  at  J'  take  place  sixteen 
and  a  half  minutes  too  late.  What  is  the  reason?  Is 
the  celestial  chronometry  getting  deranged  ?  No,  indeed ; 
these  great  worlds  swing  never  an  inch  out  of  place,  nor 
a  second  out  of  time.  By  going  to  the  other  side  of  the 
sun  the  earth  is  18^,000,000  miles  farther  from  Jupiter, 
and  the  light  that  brings  the  intelligence  of  that  eclipse 
consumes  the  extra  time  in  going  over  the  extra  distance. 
Divide  one  by  the  other  and  we  get  the  velocity,  185,000 
miles  per  second.  That 
is  probably  correct  to 
within  a  thousand  miles. 
Methods  of  measurement 
by  the  toothed  wheel  of 
Fizeau  confirm  this  re- 
sult. Suppose  the  wheel, 
Fig.  5,  to  have  one  thou- 
sand teeth,  making  five 
revolutions  to  the  second. 
Five  thousand  flashes  of 
light  each  second  will 

dart  out.  Let  each  flash  travel  nine  miles  to  a  mirror 
and  return.  If  it  goes  that  distance  in  i0ioo  of  a  sec- 
ond, or  at  the  rate  of  180,000  miles  a  second,  the  next 
tooth  will  have  arrived  before  the  eye,  and  each  return- 
ing ray  be  cut  off.  Hasten  the  revolutions  a  little,  and 
the  next  notch  will  then  admit  the  ray,  on  its  return,  that 
went  out  of  each  previous  notch :  the  eighteen  miles  hav- 
ing been  traversed  meanwhile.  The  result  of  experi- 
ments by  Lieut.  Michelson,  as  given  Sept.,  1879,  is  186,305 
miles  per  second, which  cannot  be  fifty  miles  from  correct. 
When  we  take  instantaneous  photographs  by  the  ex- 


Fig.  5.— Measuring  the  Velocity  of  Light. 


24:  CREATIVE  PROGRESS. 

posure  of  the  sensitive  plate  -jimnr  Pai*t  of  a  second,  a 
stream  of  light  nine  miles  long  dashes  in  upon  the  plate 
in  that  very  brief  period  of  time. 

The  highest  velocity  we  can  give  a  rifle-ball  is  2000 
feet  a  second,  the  next  second  it  is  only  1500  feet,  and 
soon  it  comes  to  rest.  We  cannot  compact  force  enough 
behind  a  bit  of  lead  to  keep  it  flying.  But  light  flies 
unweariedly  and  without  diminution  of  speed.  When. 
it  has  come  from  the  sun  in  eight  minutes,  Alpha  Cen- 
tauri  in  three  years,  Polaris  in  forty -five  years,  other 
stars  in  one  thousand,  its  wings  are  in  nowise  fatigued, 
nor  is  the  rapidity  of  its  flight  slackened  in  the  least. 

It  is  not  the  transactions  of  to-day  that  we  read  in 
the  heavens,  but  it  is  history,  some  of  it  older  than  the 
time  of  Adam.  Those  stars  may  have  been  smitten  out 
of  existence  decades  of  centuries  ago,  but  their  poured- 
out  light  is  yet  flooding  the  heavens. 

It  can  go  both  ways  at  once  in  the  same  place,  without 
interference.  We  see  the  light  reflected  from  the  new 
moon  to  the  earth ;  reflected  back  from  the  house-tops, 
fields,  and  waters  of  earth,  to  the  moon  again,  and  from 
the  moon  to  us  once  more — three  times  in  opposite  di- 
rections, in  the  same  place,  without  interference,  and 
thus  we  see  "  the  old  moon  in  the  arms  of  the  new." 

Constitution  of  Light. 

Light  was  once  supposed  to  be  corpuscular,  or  con- 
sisting of  transmitted  particles.  It  is  now  known  to  be 
the  result  of  undulations  in  ether.  Reference  has  been 
made  to  the  minuteness  of  these  undulations.  Their 
velocity  is  equally  wonderful.  Put  a  prism  of  glass 
into  a  ray  of  light  coming  into  a  dark  room,  and  it  is 


FORCES  OF  THE  SUNBEAM. 


25 


instantly  turned  out  of  its  course,  some  parts  more  and 
some  less,  according  to  the  number  of  vibrations,  and  ap- 
pears as  the  seven  colors  on  different  parts  of  the  screen. 
Fig.  6  shows  the  arrangement  of  colors,  and  the  number 
of  millions  of  millions  of  vibrations  per  second  of  each. 


V,  716  to  765 
I,  667  to  699 
B,  653  to  658 
G,  562  to  610 
Y,  510  to  549 
O,  478  to  510 
R,  396  to  470 


Fig.  6.— White  Light  resolved  into  Colors. 

But  the  different  divisions  we  call  colors  are  not  colors 
in  themselves  at  all,  but  simply  a  different  number  of 
vibrations.  Color  is  all  in  the  eye.  Violet  has  in  dif- 
ferent places  from  716  to  765,000,000,000,000  of  vibra- 
tions per  second ;  red  has,  in  different  places,  from  396 
to  470,000,000,000,000  vibrations  per  second.  None  of 
these  in  any  sense  are  color,  but  affect  the  eye  different- 
ly, and  we  call  these  different  effects  color.  They  are 
simply  various  velocities  of  vibration.  An  object,  like 
one  kind  of  stripe  in  our  flag,  which  absorbs  all  kinds 
of  vibrations  except  those  between  396  and  470,000,000,- 
000,000,  and  reflects  those,  appears  red  to  us.  The  field 
for  the  stars  absorbs  and  destroys  all  but  those  vibra- 
tions numbering  about  653,000,000,000,000  of  vibra- 

2 


26  CREATIVE  PROGRESS. 

tions  per  second.  A  color  is  a  constant  creation.  Light 
makes  momentary  color  in  the  flag.  Drake  might  have 
written,  in  the  continuous  present  as  well  as  in  the  past, 

"  Freedom  mingles  with  its  gorgeous  dyes 
The  milky  baldrick  of  the  skies, 
And  stripes  its  pure  celestial  white 
With  streakings  of  the  morning  light." 

Every  little  pansy,  tender  as  fancy,  pearled  with  eva- 
nescent dew,  fresh  as  a  new  creation  of  sunbeams,  has 
power  to  suppress  in  one  part  of  its  petals  all  vibrations 
we  call  red,  in  another  those  we  call  yellow,  and  pur- 
ple, and  reflect  each  of  these  in  other  parts  of  the  same 
tender  petal.  "Pansies  are  for  thoughts,"  even  more 
thoughts  than  poor  Ophelia  knew.  A  cloud  of  smoke 
that  is  dense  enough  to  absorb  all  the  faster  and  weaker 
vibrations,  leaving  only  the  stronger  to  come  through, 
will  show  the  sun  as  red ;  because  the  vibrations  that 
produce  the  impression  we  have  so  named  are  the  only 
ones  that  have  vigor  enough  to  get  through.  It  is  like 
an  army  charging  upon  a  fortress.  Under  the  deadly 
fire  and  fearful  obstructions  six-sevenths  go  down,  but 
one-seventh  comes  through  with  the  glory  of  victory 
upon  its  face. 

Light  comes  in  undulations  to  the  eye,  as  tones  of 
sound  to  the  ear.  Must  not  light  also  sing?  The  lowest 
tone  we  can  hear  is  made  by  16.5  vibrations  of  air  per 
second ;  the  highest,  so  shrill  and  "fine  that  nothing  lives 
'twixt  it  and  silence,"  is  made  by  38,000  vibrations  per 
second.  Between  these  extremes  lie  eleven  octaves ;  C 
of  the  G  clef  having  25S-J  vibrations  to  the  second,  and 
its  octave  above  517^.  Not  that  sound  vibrations  cease 


FORCES  OF  THE  SUNBEAM.  27 

at  38,000,  but  our  organs  are  not  fitted  to  hear  beyond 
those  limitations.  If  our  ears  were  delicate  enough,  we 
could  hear  even  up  to  the  almost  infinite  vibrations  of 
light.  In  one  of  those  semi -inspirations  we  find  in 
Shakspeare's  works,  he  says — 

"  There's  not  the  smallest  orb  which  thou  beholdest, 
But  in  his  motion  like  an  angel  sings, 
Still  quiring  to  the  young-eyed  cherubim. 
Such  harmony  is  in  immortal  souls; 
But,  whilst  this  muddy  vesture  of  decay 
Doth  grossly  close  it  in,  we  cannot  hear  it." 

And  that  older  poetry  which  is  always  highest  truth 
says,  "The  morning  stars  sing  together."  We  miscon- 
strued another  passage  which  we  could  not  understand, 
and  did  not  dare  translate  as  it  was  written,  till  science 
crept  up  to  a  perception  of  the  truth  that  had  been  stand- 
ing there  for  ages,  waiting  a  mind  that  could  take  it 
in.  Now  we  read  as  it  is  written — "  Thou  makest  the 
out-goings  of  the  morning  and  evening  to  sing."  Were 
our  senses  fine  enough,  we  could  hear  the  separate  key- 
note of  every  individual  star.  Stars  differ  in  glory  and 
in  power,  and  so  in  the  volume  and  pitch  of  their  song. 
Were  our  hearing  sensitive  enough,  we  could  hear  not 
only  the  separate  key-notes  but  the  infinite  swelling 
harmony  of  these  myriad  stars  of  the  sky,  as  they  pour 
their  mighty  tide  of  united  anthems  in  the  ear  of  God  : 

"  In  reason's  ear  i\\zy  all  rejoice, 
And  utter  forth  a  glorious  voice. 
Forever  singing,  as  they  shine, 
The  hand  that  made  us  is  divine." 

This  music  is  not  monotonous.  Stars  draw  near  each 
other,  and  make  a  light  that  i$  unapproachable  by  mor- 


28  CREATIVE  PROGRESS. 

tals;  then  the  music  swells  beyond  our  ability  to  en- 
dure. They  recede  far  away,  making  a  light  so  dim 
that  the  music  dies  away,  so  near  to  silence  that  only 
spirits  can  perceive  it.  No  wonder  God  rejoices  in  his 
works.  They  pour  into  his  ear  one  ceaseless  tide  of 
rapturous  song. 

Our  senses  are  limited — we  have  only  five,  but  there 
is  room  for  many  more.  Some  time  we  shall  be  taken 
out  of  "  this  muddy  vesture  of  decay,"  no  longer  see 
the  universe  through  crevices  of  our  prison-house,  but 
shall  range  through  wider  fields,  explore  deeper  mys- 
teries, and  discover  new  worlds,  hints  of  which  have 
never  yet  been  blown  across  the  wide  Atlantic  that 
rolls  between  them  and  men  abiding  in  the  flesh. 

Chemistry  of  Suns  revealed  by  Light. 

"When  we  examine  the  assemblage  of  colors  spread 
from  the  white  ray  of  sunlight,  we  do  not  find  red  sim- 
ple red,  yellow  yellow,  etc.,  but  there  is  a  vast  number 
of  fine  microscopic  lines  of  various  lengths,  parallel — 
here  near  together,  there  far  apart,  always  the  same 
number  and  the  same  relative  distance,  when  the  same 
light  and  prism  are  used.  What  new  alphabets  to  new 
realms  of  knowledge  are  these  !  Remember,  that  what 
we  call  colors  are  only  various  numbers  of  vibrations  of 
ether.  Remember,  that  every  little  group  in  the  infinite 
variety  of  these  vibrations  may  be  affected  differently 
from  every  other  group.  One  number  of  these  is  bent 
by  the  prism  to  where  we  see  what  we  call  the  violet, 
another  number  to  the  place  we  call  red.  All  of  the 
vibrations  are  destroyed  when  they  strike  a  surface  we 
call  black.  A  part  of  them  are  destroyed  when  they 


FORCES  OF  THE  SUNBEAM.  29 

strike  a  substance  we  call  colored.  The  rest  are  reflect- 
ed, and  give  the  impression  of  color.  In  one  place  on 
the  flag  of  our  nation  all  vibrations  are  destroyed  ex- 
cept the  red ;  in  another,  all  but  the  blue.  Perhaps  on 
that  other  gorgeous  flag,  not  of  our  country  but  of  our 
sun,  the  flag  we  call  the  solar  spectrum,  all  vibrations 
are  destroyed  where  these  dark  lines  appear.  Perhaps 
this  effect  is  not  produced  by  the  surface  upon  which 
the  rays  fall,  but  by  some  specific  substance  in  the  sun. 
This  is  just  the  truth.  Light  passing  through  vapor  of 
sodium  has  the  vibrations  that  would  fall  on  two  nar- 
row lines  in  the  yellow  utterly  destroyed,  leaving  two 
black  spaces.  Light  passing  through  vapor  of  burning 
iron  has  some  four  hundred  numbers  or  kinds  of  vibra- 
tions destroyed,  leaving  that  number  of  black  lines; 
but  if  the  salt  or  iron  be  glowing  gas,  in  the  source  of 
the  light  itself  the  same  lines  are  bright  instead  of 
dark. 

Thus  we  have  brought  to  our  doors  a  readable  rec- 
ord of  the  very  substances  composing  every  world  hot 
enough  to  shine  by  its  own  light.  Thus,  while  our  flag 
means  all  we  have  of  liberty,  free  as  the  winds  that  kiss 
it,  and  bright  as  the  stars  that  shine  in  it,  the  flag  of  the 
sun  means  all  that  it  is  in  constituent  elements,  all  that 
it  is  in  condition. 

We  find  in  our  sun  many  substances  known  to  exist 
in  the  earth,  and  some  that  we  had  not  discovered  when 
the  sun  wrote  their  names,  or  rather  made  their  mark, 
in  the  spectrum.  Thus,  also,  we  find  that  Betelguese 
and  Algol  are  without  any  perceivable  indications  of 
hydrogen,  and  Sirius  has  it  in  abundance.  What  a  sense 
of  acquaintanceship  it  gives  us  to  look  up  and  recognize 


30  CREATIVE  PROGRESS. 

the  stars  whose  very  substance  we  know !  If  we  were 
transported  thither,  or  beyond,  we  should  not  be  alto- 
gether strangers  in  an  unknown  realm. 

But  the  stars  differ  in  their  constituent  elements; 
every  ray  that  flashes  from  them  bears  in  its  very  be- 
ing proofs  of  what  they  are.  Hence  the  eye  of  Omni- 
science, seeing  a  ray  of  light  anywhere  in  the  universe, 
though  gone  from  its  source  a  thousand  years,  would  be 
able  to  tell  from  what  orb  it  originally  came. 

Creative  Force  of  Light. 

Just  above  the  color  vibrations  of  the  nnbraided  sun- 
beam, above  the  violet,  which  is  the  highest  number 
our  eyes  can  detect,  is  a  chemical  force ;  it  works  the 
changes  on  the  glass  plate  in  photography ;  it  transfig- 
ures the  dark,  cold  soil  into  woody  fibre,  green  leaf, 
downy  rose  petals,  luscious  fruit,  and  far  pervasive 
odor ;  it  flushes  the  wide  acres  of  the  prairie  with  grass 
and  flowers,  fills  the  valleys  with  trees,  and  covers  the 
hills  with  corn,  a  single  blade  of  which  all  the  power 
of  man  could  not  make. 

This  power  is  also  fit  and  able  to  survive.  The  en- 
gineer Stephenson  once  asked  Dr.  Buckland,  "  What 
is  the  power  that  drives  that  train?"  pointing  to  one 
thundering  by.  "  Well,  I  suppose  it  is  one  of  your  big 
engines."  "  But  what  drives  the  engine  ?"  "  Oh,  very 
likely  a  canny  Newcastle  driver."  "  No,  sir,"  said  the 
engineer,  "  it  is  sunshine."  The  doctor  was  too  dull  to 
take  it  in.  Let  us  see  if  we  can  trace  such  an  evident 
effect  to  that  distant  cause.  Ages  ago  the  warm  sun- 
shine, falling  on  the  scarcely  lifted  hills  of  Pennsylvania, 
caused  the  reedy  vegetation  to  grow  along  the  banks  of 


FORCES  OF  THE  SUNBEAM.  31 

shallow  seas,  accumulated  vast  amounts  of  this  vegeta- 
tion, sunk  it  beneath  the  sea,  roofed  it  over  with  sand, 
compacted  the  sand  into  rock,  and  changed'  this  vegeta- 
ble matter — the  products  of  the  sunshine — into  coal; 
and  when  it  was  ready,  lifted  it  once  »more,  all  garnered 
for  the  use  of  men,  roofed  over  with  mighty  mountains. 
AYe  mine  the  coal,  bring  out  the  heat,  raise  the  steam, 
drive  the  train,  so  that  in  the  ultimate  analyses  it  is  sun- 
shine that  drives  the  train.  These  great  beds  of  coal  are 
nothing  but  condensed  sunshine — the  sun's  great  force, 
through  ages  gone,  preserved  for  our  use  to-day.  And 
it  is  so  full  of  force  that  a  piece  of  coal  that  will  weigh 
three  pounds  (as  big  as  a  large  pair  of  fists)  has  as  much 
power  in  it  as  the  average  man  puts  into  a  day's  work. 
Three  tons  of  coal  will  pump  as  much  water  or  shovel 
as  much  sand  as  the  average  man  will  pump  or  shovel 
in  a  lifetime ;  so  that  if  a  man  proposes  to  do  nothing 
but  work  with  his  muscles,  he  had  better  dig  three  tons 
of  coal  and  set  that  to  do  his  work  and  then  die,  be- 
cause his  work  will  be  better  done,  and  without  any  cost 
for  the  maintenance  of  the  doer. 

Come  down  below  the  color  vibrations,  and  we  shall 
find  that  those  which  are  too  infrequent  to  be  visible, 
manifest  as  heat.  Katurally  there  will  be  as  many  dif- 
ferent kinds  of  heat  as  tints  of  color,  because  there  is  as 
great  a  range  of  numbers  of  vibration.  It  is  our  priv- 
ilege to  sift  them  apart  and  sort  them  over,  and  find 
what  kinds  are  best  adapted  to  our  various  uses. 

Take  an  electric  lamp,  giving  a  strong  beam  of  light 
and  heat,  and  with  a  plano-convex  lens  gather  it  into  a 
single  beam  and  direct  it  upon  a  thermometer,  twenty 
feet  away,  that  is  made  of  glass  and  filled  with  air.  The 


32  CREATIVE  PROGRESS. 

expansion  or  contraction  of  this  air  will  indicate  the 
varying  amounts  of  heat.  Watch  your  air-thermometer, 
on  which  the  beam  of  heat  is  pouring,  for  the  result. 
There  is  none.  And  yet  there  is  a  strong  current  of 
heat  there.  Put  another  kind  of  test  of  heat  beyond 
it  and  it  appears ;  coat  the  air-thermometer  with  a  bit 
of  black  cloth,  and  that  will  absorb  heat  and  reveal  it. 
But  why  not  at  first  ?  Because  the  glass  lens  stops  all 
the  heat  that  can  affect  glass.  The  twenty  feet  of  air 
absorbs  all  the  heat  that  affects  air,  and  no  kind  of  heat 
is  left  to  affect  an  instrument  made  of  glass  and  air ; 
but  there  are  kinds  of  heat  enough  to  affect  instruments 
made  of  other  things. 

A  very  strong  current  of  heat  may  be  sent  right 
through  the  heart  of  a  block  of  ice  without  melting  the 
ice  at  all  or  cooling  off  the  heat  in  the  least.  It  is  done 
in  this  way :  Send  the  beam  of  heat  through  water  in 
a  glass  trough,  and  this  absorbs  all  the  heat  that  can 
affect  water  or  ice,  getting  itself  hot,  and  leaving  all 
other  kinds  of  heat  to  go  through  the  ice  beyond ;  and 
appropriate  tests  show  that  as  much  heat  comes  out  on 
the  other  side  as  goes  in  on  this  side,  and  it  does  not 
melt  the  ice  at  all.  Gunpowder  may  be  exploded  by 
heat  sent  through  ice.  Dr.  Kane,  years  ago,  made  this 
experiment.  He  was  coming  down  from  the  north, 
and  fell  in  with  some  Esquimaux,  whom  he  was  anx- 
ious to  conciliate.  He  said  to  the  old  wizard  of  the 
tribe,  "I  am  a  wizard;  I  can  bring  the  sun  down  out 
of  the  heavens  with  a  piece  of  ice."  That  was  a  good 
deal  to  say  in  a  country  where  there  was  so  little  sun. 
"  So,"  he  writes,  "  I  took  my  hatchet,  chipped  a  small 
piece  of  ice  into  the  form  of  a  double  -  convex  lens, 


FORCES   OF  THE  SUNBEAM.  33 

smoothed  it  with  my  warm  hands,  held  it  up  to  the  sun, 
and,  as  the  old  man  was  blind,  I  kindly  burned  a  blister 
on  the  back  of  his  hand  to  show  him  I  could  do  it." 

These  are  simple  illustrations  of  the  various  kinds  of 
heat.  The  best  furnace  or  stove  ever  invented  con- 
sumes fifteen  times  as  much  fuel  to  produce  a  given 
amount  of  heat  as  the  furnace  in  our  bodies  consumes 
to  produce  a  similar  amount.  We  lay  in  our  supplies 
of  carbon  at  the  breakfast,  dinner,  and  supper  table,  and 
keep  ourselves  warm  by  economically  burning  it  with 
the  oxygen  we  breathe. 

Heat  associated  with  light  has  very  different  quali- 
ties from  that  which  is  not.  Sunlight  melts  ice  in  the 
middle,  bottom,  and  top  at  once.  Ice  in  the  spring-time 
is  honey-combed  throughout.  A  piece  of  ice  set  in  the 
summer  sunshine  crumbles  into  separate  crystals.  Dark 
heat  only  melts  the  surface. 

Nearly  all  the  heat  of  the  sun  passes  through  glass 
without  hinderance ;  but  take  heat  from  white-hot  plat- 
inum and  only  seventy-six  per  cent,  of  it  goes  through 
glass,  twenty -four  per  cent,  being  so  constituted  that 
it  cannot  pass  with  facility.  Of  heat  from  copper  at 
752°  only  six  per  cent,  can  go  through  glass,  the  other 
ninety-four  per  cent,  being  absorbed  by  it. 

The  heat  of  the  sunbeam  goes  through  glass  without 
any  hinderance  whatever.  It  streams  into  the  room 
as  freely  as  if  there  were  no  glass  there.  But  what  if 
the  furnace  or  stove  heat  went  through  glass  with  equal 
facility  ?  We  might  as  well  try  to  heat  our  rooms  with 
the  window-panes  all  out,  and  the  blast  of  winter  sweep- 
ing through  them. 

The  heat  of  the  sun,  by  its  intense  vibrations,  comes 

2* 


M  CREATIVE  PROGRESS. 

to  the  earth  dowered  with  a  power  which  pierces  the 
miles  of  our  atmosphere,  but  if  our  air  were  as  pervious 
to  the  heat  of  the  earth,  this  heat  would  fly  away  every 
night,  and  our  temperature  would  go  down  to  200°  be- 
low zero.  This  heat  comes  with  the  light,  and  then, 
dissociated  from  it,  the  number  of  its  vibrations  lessen- 
ed, it  is  robbed  of  its  power  to  get  away,  and  remains 
to  work  its  beneficent  ends  for  our  good. 

Worlds  that  are  so  distant  as  to  receive  only  -foVff  °^ 
the  heat  we  enjoy,  may  have  atmospheres  that  retain  it 
all.  Indeed  it  is  probable  that  Mars,  that  receives  but 
one-quarter  as  much  heat  as  the  earth,  has  a  tempera- 
ture as  high  as  ours.  The  poet  drew  on  his  imagination 
when  he  wrote : 

"  Who  there  inhabit  must  have  other  powers, 
Juices,  and  veins,  and  sense  and  life  than  ours ; 
One  moment's  cold  like  theirs  would  pierce  the  bone, 
Freeze  the  heart's  blood,  and  turn  us  all  to  stone." 

The  'power  that  journeys  along  the  celestial  spaces 
in  the  flashing  sunshine  is  beyond  our  comprehension. 
It  accomplishes  with  ease  what  man  strives  in  vain  to 
do  with  all  his  strength.  At  West  Point  there  are  some 
links  of  a  chain  that  was  stretched  across  the  river  to 
prevent  British  ships  from  ascending;  these  links  were 
made  of  two-and-a-quarter-inch  iron.  A  powerful  loco- 
motive might  tug  in  vain  at  one  of  them  and  not  stretch 
it  the  thousandth  part  of  an  inch.  But  the  heat  of  a 
single  gas-burner,  that  glows  with  the  preserved  sun- 
light of  other  ages,  when  suitably  applied  to  the  link, 
stretches  it  with  ease ;  such  enormous  power  has  a  little 
heat.  There  is  a  certain  iron  bridge  across  the  Thames 
at  London,  resting  on  arches.  The  warm  sunshine,  act- 


FORCES  OF  THE  SUNBEAM.  35 

ing  upon  the  iron,  stations  its  particles  farther  and  far- 
ther apart.  Since  the  bottom  cannot  give  way  the 
arches  must  rise  in  the  middle.  As  they  become  long- 
er they  lift  the  whole  bridge,  and  all  the  thundering 
locomotives  and  miles  of  goods-trains  cannot  bring  that 
bridge  down  again  until  the  power  of  the  sunshine  has 
been  withdrawn.  There  is  Bunker  Hill  Monument, 
thirty-two  feet  square  at  the  base,  with  an  elevation  of 
two  hundred  and  twenty  feet.  The  sunshine  of  every 
summer's  day  takes  hold  of  tbat  mighty  pile  of  granite 
with  its  aerial  fingers,  lengthens  the  side  affected,  and 
bends  the  whole  great  mass  as  easily  as  one  would  bend 
a  whipstock.  A  few  years  ago  we  hung  a  plummet  from 
the  top  of  this  monument  to  the  bottom.  At  9  A.M.  it 
began  to  move  toward  the  west;  at  noon  it  swung 
round  toward  the  north ;  in  the  afternoon  it  went  east 
of  where  it  first  was,  and  in  the  night  it  settled  back  to 
its  original  place. 

The  sunshine  says  to  the  sea,  held  in  the  grasp  of 
gravitation,  "  Rise  from  your  bed  !  Let  millions  of  tons 
of  water  fly  on  the  wings  of  the  viewless  air,  hundreds 
of  miles  to  the  distant  mountains,  and  pour  there  those 
millions  of  tons  that  shall  refresh  a  whole  continent, 
and  shall  gather  in  rivers  fitted  to  bear  the  commerce 
and  the  navies  of  nations."  Gravitation  says,  "  I  will 
hold  every  particle  of  this  ocean  as  near  the  centre  of 
the  earth  as  I  can."  Sunshine  speaks  with  its  word  of 
power,  and  says,  "  Up  and  away !"  And  in  the  wreath- 
ing mists  of  morning  these  myriads  of  tons  rise  in  the 
air,  fly  away  hundreds  of  miles,  and  supply  all  the  Ni- 
agaras, Mississippis  and  Amazons  of  earth.  The  sun 
says  to  the  earth,  wrapped  in  the  mantle  of  winter, 


36  CREATIVE  PROGRESS. 

"  Bloom  again ;"  and  the  snows  melt,  the  ice  retires, 
and  vegetation  breaks  forth,  birds  sing,  and  spring  is 
about  us. 

Thus  it  is  evident  that  every  force  is  constitutional- 
ly arranged  to  be  overcome  by  a  higher,  and  all  by  the 
highest.  Gravitation  of  earth  naturally  and  legitimate- 
ly yields  to  the  power  of  the  sun's  heat,  and  then  the 
waters  fly  into  the  clouds.  It  as  naturally  and  legiti- 
mately yields  to  the  power  of  mind,  and  the  waters  of 
the  Ked  Sea  are  divided  and  stand  "  upright  as  an  heap." 
Water  naturally  bursts  into  flame  when  a  bit  of  potas- 
sium is  thrown  into  it,  and  as  naturally  when  Elijah 
calls  the  right  kind  of  fire  from  above.  What  seems 
a  miracle,  and  in  contravention  of  law,  is  only  the  con- 
stitutional exercise  of  higher  force  over  forces  organ- 
ized to  be  swayed.  If  law  were  perfectly  rigid,  there 
could  be  but  one  force ;  but  many  grades  exist  from 
cohesion  to  mind  and  spirit.  The  highest  forces  are 
meant  to  have  victory,  and  thus  give  the  highest  order 
and  perfectness. 

Across  the  astronomic  spaces  reach  all  these  powers, 
making  creation  a  perpetual  process  rather  than  a  single 
act.  It  almost  seems  as  if  light,  in  its  varied  capacities, 
were  the  embodiment  of  God's  creative  power;  as  if, 
having  said,  "  Let  there  be  light,"  he  need  do  nothing 
else,  but  allow  it  to  carry  forward  the  creative  processes 
to  the  end  of  time.  It  was  Newton,  one  of  the  earliest 
and  most  acute  investigators  in  this  study  of  light,  who 
said,  "  I  seem  to  have  wandered  on  the  shore  of  Truth's 
great  ocean,  and  to  have  gathered  a  few  pebbles  more 
beautiful  than  common ;  but  the  vast  ocean  itself  rolls 
before  me  undiscovered  and  unexplored." 


EXPERIMENTS. 


37 


EXPERIMENTS  WITH  LIGHT. 

A  light  set  in  a  room  is  seen  from  every  place ;  hence  light  streams  in 
every  possible  direction.  If  put  in  the  centre  of  a  hollow  sphere,  every 
point  of  the  surface  will  be  equally  illumined.  If  put  in  a  sphere  of 
twice  the  diameter,  the  same  light  will  fall  on  all  the  larger  surface.  The 
surfaces  of  spheres  are  as  the  squares  of  their  diameters ;  hence,  in  the 
larger  sphere  the  surface  is  illumined  only  one -quarter  as  much  as  the 
smaller.  The  same  is  true  of  large  and  small  rooms.  In  Fig.  7  it  is  ap- 


Fig.  7. 

parent  that  the  light  that  falls  on  the  first  square  is  spread,  at  twice  the 
distance,  over  the  second  square,  which  is  four  times  as  large,  and  at  three 
times  the  distance  over  nine  times  the  surface.  The  van-ing  amount  of 
light  received  by  each  planet  is  also  shown  in  fractions  above  each  world, 
the  amount  received  by  the  earth  being  1. 


Fig.  8.— Measuring  Intensities  of  Lights. 

The  intensity  of  light  is  easily  measured.  Let  two  lights  of  different 
brightness,  as  in  Fig.  8,  cast  shadows  on  the  same  screen.  Arrange  them 
as  to  distance  so  that  both  shadows  shall  be  equally  dark.  Let  them  fall 
side  by  side,  and  study  them  carefully.  Measure  the  respective  distances. 
Suppose  one  is  twenty  inches,  the  other  forty.  Light  varies  as  the  square 


38  CREATIVE  PROGRESS. 

of  the  distance :  the  square  of  20  is  400,  of  40  is  1600.     Divide  1600  by 
400,  and  the  result  is  that  one  light  is  four  times  as  bright  as  the  other. 

Light  can  be  handled,  directed,  and  bent,  as  well  as  iron  bars.  Darken 
a  room  and  admit  a  beam  of  sunlight  through  a  shutter,  or  a  ray  of  lamp- 
light through  the  key-hole.  If  there  is  dust  in  the  room  it  will  be  observed 
that  light  goes  in  straight  lines.  Because  of  this  men  are  able  to  arrange 
houses  and  trees  in  rows,  the  hunter  aims  his  rifle  correctly,  and  the  as- 
tronomer projects  straight  lines  to  infinity.  Take  a  hand-mirror,  or  bet- 


Fig.  9 Reflection  and  Diffusion  of  Ligh 


ter,  a  piece  of  glass  coated  on  one  side  with  black  varnish,  and  you  can 
send  your  ray  anywhere.  By  using  two  mirrors,  or  having  an  assistant 
and  using  several,  you  can  cause  a  ray  of  light  to  turn  as  many  corners 
as  you  please.  I  once  saw  Mr.  Tyndall  send  a  ray  into  a  glass  jar  filled 
with  smoke  (Fig.  9).  Admitting  a  slender  ray  through  a  small  hole  in  a 
card  over  the  mouth,  one  ray  appeared ;  removing  the  cover,  the  whole 
jar  was  luminous ;  as  the  smoke  disappeared  in  spots  cavities  of  dark- 
ness appeared.  Turn  the  same  ray  into  a  tumbler  of  water,  it  becomes 


EXPERIMENTS. 


39 


faintly  visible ;  stir  into  it  a  teaspoonful  of  milk,  then  turn  in  the  ray  of 
sunlight,  and  it  glows  like  a  lamp,  illuminating  the  whole  room.  These 
experiments  show  how  the  straight  rays  of  the  sun  are  diffused  in  every 
direction  over  the  earth. 

Set  a  small  light  near  one  edge  of  a  mirror ;  then,  by  putting  the  eye 
near  the  opposite  edge,  you  see  almost  as  many  flames  as  you  please  from 
the  multiplied  reflections.  How  can  this  be  accounted  for  ? 

Into  your  beam  of  sunlight,  admitted  through  a  half-inch  hole,  put  the 
mirror  at  an  oblique  angle  ;  you  can  arrange  it  so  as  to  throw  half  a  dozen 
bright  spots  on  the  opposite  wall. 

In  Fig.  10  the  sunbeam  enters  at  A,  and,  striking  the  mirror  m  at  a, 
is  partly  reflected  to  1  on  the  wall,  and  partly  enters  the  glass,  passes 


Fig.  10.— Mauifold  Reflections. 

through  to  the  silvered  back  at  B,  and  is  totally  reflected  to  6,  where  it 
again  divides,  some  of  it  going  to  the  wall  at  2,  and  the  rest,  continuing 
to  make  the  same  reflections  and  divisions,  causes  spots  3,  4,  5,  etc.  The 
brightest  spot  is  at  No.  2,  because  the  silvered  glass  at  B  is  the  best  re- 
flector and  has  the  most  light. 

When  the  discovery  of  the  moons  of  Mars  was  announced  in  1877,  it 
was  also  widely  published  that  they  could  be  seen  by  a  mirror.  Of  course 
this  is  impossible.  The  point  of  light  mistaken  for  the  moon  in  this  sec- 
ondary reflection  was  caused  by  holding  the  mirror  in  an  oblique  position. 

Take  a  small  piece  of  mirror,  say  an  inch  in  surface,  and  putting  under 
it  three  little  pellets  of  wax,  putty,  or  clay,  set  it  on  the  wrist,  with  one  of 
the  pellets  on  the  pulse.  Hold  the  mirror  steadily  in  the  beam  of  ligM, 
and  the  frequency  and  prominence  of  each  pulse-beat  will  be  indicated  by 
the  tossing  spot  of  light  on  the  Avail.  If  the  operator  becomes  excited 
the  fact  will  be  evident  to  all  observers. 

Place  a  coin  in  a  basin  (Fig.  11),  and  set  it  so  that  the  rim  will  con- 
ceal the  coin  from  the  eye.  Pour  in  water,  and  the  coin  will  appear 


CREATIVE  PROGRESS. 


Fig.  11. 


to  rise  into  sight.  When  light  passes 
from  a  medium  of  one  density  to  a 
medium  of  another,  its  direction  is 
changed.  Thus  a  stick  in  water  seems 
bent.  Ships  below  the  horizon  are 
sometimes  seen  above,  because  of  the 


different  density  of  the  layers  of  air. 

Thus  light  coming  from  the  interstellar  spaces,  and  entering  our  atmos- 
phere, is  bent  down  more  and  more  by  its  increasing  density.  The  effect 
is  greatest  when  the  sun  or  star  is  near  the  horizon,  none  at  all  in  the 
zenith.  This  brings  the  object  into  view  before  it  is  risen.  Allowance 
for  this  displacement  is  made  in  all  delicate  astronomical  observations. 


Fig.  12. — Atmospherical  Refraction. 

Notice  on  the  floor  the  shadow  of  the  window-frames.  The  glass  of 
almost  every  window  is  so  bent  as  to  turn  the  sunlight  aside  enough  to 
obliterate  some  of  the  shadows  or  increase  their  thickness. 

DECOMPOSITION  OF  LIGHT. 

Admit  the  sunbeam  through  a  slit  one  inch  long  and  one-twentieth  of 
an  inch  wide.  Pass  it  through  a  prism.  Either  purchase  one  or  make  it 
of  three  plain  pieces  of  glass  one  and  a  half  inch  wide  by  six  inches  long, 
fastened  together  in  triangular  shape — fasten  the  edges  with  hot  wax  and 
fill  it  with  water ;  then  on  a  screen  or  wall  you  will  have  the  colors  of  the 
rainbow,  not  merely  seven  but  seventy,  if  your  eyes  are  sharp  enough. 

Take  a  bit  of  red  paper  that  matches  the  red  color  of  the  spectrum. 
Move  it  along  the  line  of  colors  toward  the  violet.  In  the  orange  it  is 
dark,  in  the  yellow  darker,  in  the  green  and  all  beyond,  black.  That  is 
because  there  are  no  more  red  rays  to  be  reflected  by  it.  So  a  green  ob- 
ject is  true  to  its  color  only  in  the  green  rays,  and  black  elsewhere.  All 
these  colors  may  be  recombined  by  a  second  prism  into  white  light. 


III. 

ASTRONOMICAL   INSTRUMENTS. 

The  eyes  of  the  Lord  are  in  every  place."  —  Proverbs  xv. 


"Man,  having  one  kind  of  an  eye  given  him  by  his  Maker,  proceeds  to 
construct  two  other  kinds.  He  makes  one  that  magnifies  invisible  objects 
thousands  of  times,  so  that  a  dull  razor-edge  appears  as  thick  as  three 
fingers,  until  the  amazing  beauty  of  color  and  form  in  infinitesimal  ob- 
jects is  entrancingly  apparent,  and  he  knows  that  God's  care  of  least 
things  is  infinite.  Then  he  makes  the  other  kind  four  or  six  feet  in  di- 
ameter, and  penetrates  the  immensities  of  space  thousands  of  tines  be- 
yond where  his  natural  eye  can  pierce,  until  he  sees  that  God  s  immensi- 
ties of  worlds  are  infinite  also." — BISHOP  FOSTER. 


THE  TELESCOPE.  43 


III. 
THE    TELESCOPE. 

FREQFEXT  allusion  has  been  made  in  the  previous 
chapter  to  discovered  results.  It  is  necessary  to  under- 
stand more  clearly  the  process  by  which  such  results 
have  been  obtained.  Some  astronomical  instruments 
are  of  the  simplest  character,  some  most  delicate  and 
complex.  "Vyhen  a  man  smokes  a  piece  of  glass,  in  or- 
der to  see  an  eclipse  of  the  sun,  he  makes  a  simple 
instrument.  Ferguson,  lying  on  his  back  and  slipping 
beads  on  a  string  at  a  certain  distance  above  his  eye, 
measured  the  relative  distances  of  the  stars.  The  use 
of  more  complex  instruments  commenced  when  Galileo 
applied  the  telescope  to  the  heavens.  He  cannot  be  said 
to  have  invented  the  telescope,  but  he  certainly  con- 
structed his  own  without  a  pattern,  and  used  it  to  good 
purpose.  It  consists  of  a  lens,  O  B  (Fig.  13),  which 


^ 


B 

Fig.  13.—  Refracting  Telescope. 


acts  as  a  multiple  prism  to  bend  all  the  rays  to  one 
point  at  R.  Place  the  eye  there,  and  it  receives  as 
much  light  as  if  it  were  as  large  as  the  lens  O  B.  The 
rays,  however,  are  convergent,  and  the  point  difficult  to 


44  ASTRONOMICAL  INSTRUMENTS. 

find.  Hence  there  is  placed  at  R  a  concave  lens,  pass- 
ing through  which  the  rays  emerge  in  parallel  lines,  and 
are  received  by  the  eye.  Opera-glasses  are  made  upon 
precisely  this  principle  to-day,  because  they  can  be  made 
conveniently  short. 

If,  instead  of  a  concave  lens  at  R,  converting  the  con- 
verging rays  into  parallel  ones,  we  place  a  convex  or 
magnifying  lens,  the  minute  image  is  enlarged  as  much 
as  an  object  seems  diminished  when  the  telescope  is 
reversed.  This  is  the  grand  principle  of  the  refracting 
telescope.  Difficulties  innumerable  arise  as  we  attempt 
to  enlarge  the  instruments.  These  have  been  over- 
come, one  after  another,  until  it  is  now  felt  that  the 
best  modern  telescope,  with  an  object  lens  of  twenty-six 
inches,  has  fully  reached  the  limit  of  optical  power. 

The  Reflecting  Telescope. 

This  is  the  only  kind  of  instrument  differing  radi- 
cally from  the  refracting  one  already  described.  It  re- 
ceives the  light  in  a  concave  mirror,  M  (Fig.  14),  which 


Fig.  14.— Reflecting  Telescope. 

reflects  it  to  the  focus  F,  producing  the  same  result  as 
the  lens  of  the  refracting  telescope.  At  B  a  mirror 
may  be  placed  obliquely,  reflecting  the  image  at  right 
angles  to  the  eye,  outside  the  tube,  in  which  case  it  is 
called  the  Newtonian  telescope ;  or  a  mirror  at  R  may 
be  placed  perpendicularly,  and  send  the  rays  through 


THE  REFLECT IX  <r    TELESCOPE.  45 

an  opening  in  the  mirror  at  M.  This  form  is  called  the 
Gregorian  telescope.  Or  the  mirror  M  may  be  slightly 
inclined  to  the  coining  rays,  so  as  to  bring  the  point  F 
entirely  outside  the  tube,  in  which  case  it  is  called  the 
Herschelian  telescope.  In  either  case  the  image  may 
be  magnified,  as  in  the  refracting  telescope. 

Reflecting  telescopes  are  made  of  all  sizes,  up  to  the 
Cyclopean  eye  of  the  one  constructed  by  Lord  Rosse, 
which  is  six  feet  in  diameter.  The  form  of  instru- 
ment to  be  preferred  depends  on  the  use  to  which  it  is 
to  be  put.  The  loss  of  light  in  passing  through  glass 
lenses  is  about  two -tenths.  The  loss  by  reflection  is 
often  one-half.  In  view  of  this  peculiarity  and  many 
others,  it  is  held  that  a  twenty-six-inch  refractor  is  fully 
equal  to  any  six-foot  reflector. 

The  mounting  of  large  telescopes  demands  the  high- 
est engineering  ability.  The  whole  instrument,  with 
its  vast  weight  of  a  twenty-six-inch  glass  lens,  with  its 
accompanying  tube  and  appurtenances,  must  be  pointed 
as  nicely  as  a  rifle,  and  held  as  steadily  as  the  axis  of 
the  globe.  To  give  it  the  required  steadiness,  the  foun- 
dation on  which  it  is  placed  is  sunk  deep  in  the  earth, 
far  from  rail  or  other  roads,  and  no  part  of  the  observ- 
atory is  allowed  to  touch  this  support.  When  a  star  is 
once  found,  the  earth  swiftly  rotates  the  telescope  away 
from  it,  and  it  passes  out  of  the  field.  To  avoid  this, 
clock-work  is  so  arranged  that  the  great  telescope  fol- 
lows the  star  by  the  hour,  if  required.  It  will  take  a 
star  at  its  eastern  rising,  and  hold  it  constantly  in  view 
while  it  climbs  to  the  meridian  and  sinks  in  the  west 
iFig.  15).  The  reflector  demands  still  more  difficult  en- 
gineering. That  of  Lord  Rosse  has  a  metallic  mirror 


4:6 


ASTRONOMICAL  INSTRUMENTS. 


Fig.  15, — Cambridge  Equatorial. 

weighing  six  tons,  a  tube  fifty-six  feet  long,  which,  with 
its  appurtenances,  weighs  seven  tons  more.  It  moves 
between  two  walls  only  20°  east  and  west.  The  new 
Paris  reflector  (Fig.  16)  has  a  much  wider  range  of 
movement 

The  Spectroscope. 

A  spectrum  is  a  collection  of  the  colors  which  are 
dispersed  by  a  prism  from  any  given  light.  If  it  is  sun- 
light, it  is  a  solar  spectrum;  if  the  source  of  light  is  a 


Fiji.  16.— New  Paris  Reflector. 


THE  SPECTROSCOPE.  49 

star,  candle,  glowing  metal,  or  gas,  it  is  the  spectrum  of 
a  star,  candle,  glowing  metal,  or  gas.  An  instrument 
to  see  these  spectra  is  called  a  spectroscope.  Consider- 
ing the  infinite  variety  of  light,  and  its  easy  modifica- 
tion and  absorption,  we  should  expect  an  immense 
number  of  spectra.  A  mere  prism  disperses  the  light 
so  imperfectly  that  different  orders  of  vibrations,  per- 
ceived as  colors,  are  mingled.  No  eye  can  tell  where 
one  commences  or  ends.  Such  a  spectrum  is  said  to 
be  impure.  What  we  want  is  that  each  point  in  the 
spectrum  should  be  made  of  rays  of  the  same  number 
of  vibrations.  As  we  can  let  only  a  small  beam  of  light 
pass  through  the  prism,  in  studying  celestial  objects  with 
a  telescope  and  spectroscope  we  must,  in  every  instance, 
contract  the  aperture 
of  the  instrument  un- 
til we  get  only  a  small 
beam  of  light.  In  or- 
der to  have  the  colors 
thoroughly  dispersed, 
the  best  instruments 
pass  the  beam  of  light 
through  a  series  of 
prisms  called  a  bat- 
tery, each  one  spread- 
ing farther  the  colors 
which  the  previous 
ones  had  spread.  In 
Fig.  17  the  ray  is  seen 

.  .       .          Fig.  17 — Spectroscope,  with  Battery  of  Prisms. 

entering  through  the 

telescope  A,  which  renders  the  rays  parallel,  and  pass- 
ing through  the  prisms  out  to  telescope  B,  where  the 

3 


50 


ASTR GNOMICAL  IN8TR  UMENTS. 


spectrum  can  be  examined  on  the  retina  of  the  eye  for 
a  screen.  In  order  to  still  farther  disperse  the  rays, 
some  batteries  receive  the  ray  from  the  last  prism  at  0 
upon  an  oblique  mirror,  send  it  up  a  little  to  another, 
which  delivers  it  again  to  the  prism  to  make  its  journey 
back  again  through  them  all,  and  come  out  to  be  ex- 
amined just  above  where  it  entered  the  first  prism. 

Attached  to  the  examining  telescope  is  a  diamond- 
ruled  scale  of  glass,  enabling  us  to  fix  the  position  of 
any  line  with  great  exactness. 

In  Fig.  18  is  seen,  in  the  lower  part,  a  spectrum  of 
the  sun,  with  about  a  score  of  its  thousands  of  lines 


D 


II  h  O  F  c      ft  E  DCBA 

Fig.  IS.— Spectra  of  glowing  Hydrogen  nnd  the  Sun. 

made  evident.  In  the  upper  part  is  seen  the  spectrum 
of  bright  lines  given  by  glowing  hydrogen  gas.  These 
lines  are  given  by  no  other  known  gas;  they  are  its 
autograph.  It  is  readily  observed  that  they  precisely 
correspond  with  certain  dark  lines  in  the  solar  spec- 
trum. Hence  we  easily  know  that  a  glowing  gas  gives 
the  same  bright  lines  that  it  absorbs  from  the  light  of 
another  source  passing  through  it  —  that  is,  glowing 
gas  gives  out  the  same  rays  of  light  that  it  absorbs 
when  it  is  not  glowing. 

The  subject  becomes  clearer  by  a  study  of  the  chro- 
molithic  plate.  No.  1  represents  the  solar  spectrum, 
with  a  few  of  its  lines  on  an  accurately  graduated  scale. 


THE  SPECTROSCOPE.  51 

No.  3  shows  the  bright  line  of  glowing  sodium,  and, 
corresponding  to  a  dark  line  in  the  solar  spectrum,  shows 
the  presence  of  salt  in  that  body.  No.  2  shows  that 
potassium  has  some  violet  rays,  but  not  all ;  and  there 
being,  no  dark  line  to  correspond  in  the  solar  spectrum, 
we  infer  its  absence  from  the  sun.  No.  6  shows  the 
numerous  lines  and  bands  of  barium  —  several  red, 
orange,  yellow,  and  four  are  very  bright  green  ones. 
The  lines  given  by  any  volatilized  substances  are  al- 
ways in  the  same  place  on  the  scale. 

A  patient  study  of  these  signs  of  substances  reveals 
richer  results  than  a  study  of  the  coniform  characters 
engraved  on  Assyrian  slabs;  for  one  is  the  handwri- 
ting of  men,  the  other  the  handwriting  of  God. 

One  of  the  most  difficult  and  delicate  problems  solved 
by  the  spectroscope  is  the  approach  or  departure  of  a 
light-giving  body  in  the  line  of  sight.  Stand  before  a 
locomotive  a  mile  away,  you  cannot  tell  whether  it  ap- 
proaches or  recedes,  yet  it  will  dash  by  in  a  minute. 
How  can  the  movements  of  the  stars  be  comprehended 
when  they  are  at  such  an  immeasurable  distance? 

It  can  best  be  illustrated  by  music.  The  note  C  of 
the  G  clef  is  made  by  two  hundred  and  fifty-seven  vi- 
brations of  air  per  second.  Twice  as  many  vibrations 
per  second  would  give  us  the  note  C  an  octave  above. 
Sound  travels  at  the  rate  of  three  hundred  and  sixty- 
four  yards  per  second.  If  the  source  of  these  two  hun- 
dred and  fifty -seven  vibrations  could  approach  us  at 
three  hundred  and  sixty-four  yards  per  second,  it  is  ob- 
vious that  twice  as  many  waves  would  be  put  into  a 
given  space,  and  we  should  hear  the  upper  C  when  only 
waves  enough  were  made  for  the  lower  C.  The  same 


52  ASTRONOMICAL  INSTRUMENTS. 

result  would  appear  if  we  carried  our  ear  toward  the 
sound  fast  enough  to  take  up  twice  as  many  waves  as 
though  we  stood  still.  This  is  apparent  to  every  ob- 
server in  a  railway  train.  The  whistle  of  an  approach- 
ing locomotive  gives  one  tone;  it  passes,  and  we  in- 
stantly detect  another.  Let  two  trains,  running  at  a 
speed  of  thirty-six  yards  a  second,  approach  each  oth- 
er. Let  the  whistle  of  one  sound  the  note  E,  three 
hundred  and  twenty -three  vibrations  per  second.  It 
will  be  heard  on  the  other  as  the  note  G,  three  hun- 
dred and  eighty- eight  vibrations  per  second;  for  the 
speed  of  each  train  crowds  the  vibrations  into  one-tenth 
less  room,  adding  32  +  vibrations  per  second,  making 
three  hundred  and  eighty-eight  in  all.  The  trains  pass. 
The  vibrations  are  put  into  one -tenth  more  space  by 
the  whistle  making  them,  and  the  other  train  allows 
only  nine-tenths  of  what  there  are  to  overtake  the  ear. 
Each  subtracts  32+  vibrations  from  three  hundred  and 
twenty-three,  leaving  only  two  hundred  and  fifty-eight, 
which  is  the  note  C.  Yet  the  note  E  was  constantly 
uttered. 

If  a  source  of  light  approach  or  depart,  it  will  have  a 
similar  effect  on  the  light  waves.  How  shall  we  detect 
it  ?  If  a  star  approach  us,  it  puts  a  greater  number  of 
waves  into  an  inch,  and  shortens  their  length.  If  it  re- 
cedes, it  increases  the  length  of  the  wave — puts  a  less 
number  into  an  inch.  If  a  body  giving  only  the  num- 
ber of  vibrations  we  call  green  were  to  approach  suf- 
ficiently fast,  it  would  crowd  in  vibrations  enough  to 
appear  what  we  call  blue,  indigo,  or  even  violet,  accord- 
ing to  its  speed.  If  it  receded  sufficiently  fast,  it  would 
leave  behind  it  only  vibrations  enough  to  fill  up  the 


1.  Solar  Spectrum. 

2.  Spectrum  of  Potassium 


3.  Spectrum,  « 
4  Spectrum  o 

Harper  fc-Brotli 


of  Sodium 
of  Strontium.. 

.tiers  .Kew  York, 


5.  Spectrum  of  Calcium 

6.  Spectrum,  of  Barium 


THE  SPECTROSCOPE.  53 

space  with  what  we  call  yellow,  orange,  or  red,  accord- 
ing to  its  speed ;  yet  it  would  be  green,  and  green  only, 
all  the  time.  But  how  detect  the  change?  If  red  waves 
are  shortened  they  become  orange  in  color;  and  from 
below  the  red  other  rays,  too  far  apart  to  be  seen  by  the 
eye,  being  shortened,  become  visible  as  red,  and  we  can- 
not know  that  anything  has  taken  place.  So,  if  a  star 
recedes  fast  enough,  violet  vibrations  being  lengthened 
become  indigo ;  and  from  above  the  violet  other  rays, 
too  short  to  be  seen,  become  lengthened  into  visible  vio- 
let, and  we  can  detect  no  movement  of  the  colors.  The 
dark  lines  of  the  spectrum  are  the  cutting  out  of  rays 
of  definite  wave-lengths.  If  the  color  spectrum  moves 
away,  they  move  with  it,  and  away  from  their  proper 
place  in  the  ordinary  spectrum.  If,  then,  we  find  them 
toward  the  red  end,  the  star  is  receding ;  if  toward  the 
violet  end,  it  is  approaching.  Turn  the  instrument  on 
the  centre  of  the  sun.  The  dark  lines  take  their  appro- 
priate place,  and  are  recognized  on  the  ruled  scale.  Turn 
it  on  one  edge,  that  is  approaching  us  one  and  a  quarter 
miles  a  second  by  the  revolution  of  the  sun  on  its  axis, 
the  spectral  lines  move  toward  the  violet  end ;  turn  the 
spectroscope  toward  the  other  edge  of  the  sun,  it  is  re- 
ceding from  us  one  and  a  quarter  miles  a  second  by 
reason  of  the  axial  revolution,  and  the  spectral  lines 
move  toward  the  red  end.  Turn  it  near  the  spots,  and 
it  reveals  the  mighty  up -rush  in  one  place  and  the 
down-rush  in  another  of  one  hundred  miles  a  second. 
We  speak  of  it  as  an  easy  matter,  but  it  is  a  problem  of 
the  greatest  delicacy,  almost  defying  the  mind  of  man 
to  read  the  movements  of  matter. 

It  should  be  recognized  that  Professor  Young,  of 


54  ASTRONOMICAL  INSTRUMENTS. 

Princeton,  is  the  most  successful  operator  in  this  recent 
realm  of  science.  He  already  proposes  to  correct  the 
former  estimate  of  the  sun's  axial  revolutions,  derived 
from  observing  its  spots,  by  the  surer  process  of  observ- 
ing accelerated  and  retarded  light. 

Within  a  very  few  years  this  wonderful  instrument, 
the  spectroscope,  has  made  amazing  discoveries.  In 
chemistry  it  reveals  substances  never  known  before ; 
in  analysis  it  is  delicate  to  the  detection  of  the  mill- 
ionth of  a  grain.  It  is  the  most  deft  handmaid  of 
chemistry,  the  arts,  of  medical  science,  and  astronomy. 
It  tells  the  chemical  constitution  of  the  sun,  the  move- 
ments taking  place,  the  nature  of  comets,  and  nebulae. 
By  the  spectroscope  we  know  that  the  atmospheres  of 
Venus  and  Mars  are  .like  our  own  ;  that  those  of  Jupi- 
ter and  Saturn  are  very  unlike ;  it  tells  us  which  stars 
approach  and  which  recede,  and  just  how  one  star  dif- 
fereth  from  another  in  glory  and  substance. 

In  the  near  future  we  shall  have  the  brilliant  and 
diversely  colored  flowers  of  the  sky  as  well  classified 
into  orders  and  species  as  are  the  flowers  of  the  earth. 


CELESTIAL    MEASUREMENTS. 

"Who  hath  measured  the  waters  in  the  hollow  of  his  hand,  and  meted 
out  heaven  with  the  span  ?  Mine  hand  also  hath  laid  the  foundation  of 
the  earth,  and  my  rigni  hand  hath  spanned  the  heavens." — Isa.  xl.  12; 
xlviii.  13. 


6*  Go  to  yon  tower,  where  busy  science  plies 
Her  vast  antennae,  feeling  thro1  the  skies ; 
That  little  vernier,  on  whose  slender  lines 
The  midnight  taper  tremhles  as  it  shines, 
A  silent  index,  tracks  the  planets'  inarch 
In  all  their  wanderings  thro'  the  ethereal  arch, 
Tells  through  the  mist  whd'd  cazzled  Mercury  burns, 
And  marks  the  spot  where  Uranus  returns. 

"  So,  till  by  wrong  or  negligence  effaced, 
The  living  index  which  thy  Maker  traced 
Kepeats  the  line  each  starry  virtue  draws 
Through  the  wide  circuit  of  creation's  laws : 
Still  tracks  unchanged  the  everlasting  ray 
Where  the  dark  shadows  of  temptation  stray ; 
But,  once  defaced,  forgets  the  orbs  of  light, 
And  leaves  thee  wandering  o'er  the  expanse  of  night." 

OLIVER  WENDELL  HOLMES. 


USES  OF  ASTRONOMY.  57 


IY. 

CELESTIAL  MEASUREMENTS. 

WE  know  that  astronomy  lias  what  are  called  practi- 
cal uses.  If  a  ship  had  been  driven  by  Euroclydon  ten 
times  fourteen  days  and  nights  without  sun  or  star  ap- 
pearing, a  moment's  glance  into  the  clear  sky  from  the 
heaving  deck,  by  a  very  slightly  educated  sailor,  would 
tell  within  one  hundred  rods  where  he  was,  and  de- 
termine the  distance  and  way  to  the  nearest  port.  We 
know  that,  in  all  final  and  exact  surveying,  positions 
must  be  fixed  by  the  stars.  Earth's  landmarks  are  un- 
certain and  easily  removed ;  those  which  we  get  from, 
the  heavens  are  stable  and  exact. 

In  1878  the  United  States  steam -ship  Enterprise 
was  sent  to  survey  the  Amazon.  Every  night  a  "  star 
party"  went  ashore  to  fix  the  exact  latitude  and  lon- 
gitude by  observations  of  the  stars.  Our  real  land- 
marks are  not  the  pillars  we  rear,  but  the  stars  millions 
of  miles  away.  All  our  standards  of  time  are  taken 
from  the  stars ;  every  railway  train  runs  by  their  time 
to  avoid  collision  ;  by  them  all  factories  start  and  stop. 
Indeed,  we  are  ruled  by  the  stars  even  more  than  the 
old  astrologers  imagined. 

Man's  finest  mechanism,  highest  thought,  and  broad- 
est exercise  of  the  creative  faculty  have  been  inspired 
by  astronomy.  No  other  instruments  approximate  in 
delicacy  those  which  explore  the  heavens;  no  other 


58  CELESTIAL  MEASUREMENTS. 

system  of  thought  can  draw  such  vast  and  certain  con- 
clusions from  its  premises.  "  Too  low  they  build  who 
build  beneath  the  stars ;"  we  should  lay  our  foundations 
in  the  skies,  and  then  build  upward. 

We  have  been  placed  on  the  outside  of  this  earth,  in- 
stead of  the  inside,  in  order  that  we  may  look  abroad. 
We  are  carried  about,  through  unappreciable  distance, 
at  the  inconceivable  velocity  of  one  thousand  miles  a 
minute,  to  give  us  different  points  of  vision.  The 
earth,  on  its  softly-spinning  axle,  never  jars  enough  to 
unnest  a  bird  or  wake  a  child ;  hence  the  foundations 
of  our  observatories  are  firm,  and  our  measurements  ex- 
act. Whoever  studies  astronomy,  under  proper  guid- 
ance and  in  the  right  spirit,  grows  in  thought  and  feel- 
ing, and  becomes  more  appreciative  of  the  Creator. 

Celestial  Movements. 

Let  it  not  be  supposed  that  a  mastery  of  mathematics 
and  a  finished  education  are  necessary  to  understand  the 
results  of  astronomical  research.  It  took  at  first  the 
highest  power  of  mind  to  make  the  discoveries  that 
are  now  laid  at  the  feet  of  the  lowliest.  It  took  sublime 
faith,  courage,  and  the  results  of  ages  of  experience  in 
navigation,  to  enable  Columbus  to  discover  that  path  to 
the  New  World  which  now  any  little  boat  can  follow. 
Ages  of  experience  and  genius  are  stored  up  in  a  loco- 
motive, but  quite  an  unlettered  man  can  drive  it.  It 
is  the  work  of  genius  to  render  difficult  matters  plain, 
abstruse  thoughts  clear. 

A  brief  explanation  of  a  few  terms  will  make  the  prin- 
ciples of  world  inspection  easily  understood.  Imagine 
a  perfect  circle  thirty  feet  in  diameter — that  is,  create 


USES  OF  ASTRONOMY.  •       59 

one  (Fig.  19).    Draw  through  it  a  diameter  horizontally, 
another   perpendicularly.       The    angles 
made  by  the  intersecting  lines  are  each 
said  to  be  ninety  degrees,  marked  thus  °. 
The  arc  of  a  circle  included  between  any 
two  of  the  lines  is  also  90°.     Every  cir- 
cle, great  or  small,  is  divided  into  these 
360°.     If  the  sun  rose  in  the  east  and 
came  to  the  zenith  at  noon,  it  would  have  passed  90°. 
When  it  set  in  the  west  it  would  have  traversed  half  the 
circle,  or  180°.     In  Fig.  20  the  angle  of  the  lines  meas- 


Fig.  20.— Illustration  of  Angles. 

ured  on  the  graduated  arc  is  10°.  The  mountain  is  10° 
high,  the  world  10°  in  diameter,  the  comet  moves  10°  a 
day,  the  stars  are  10°  apart.  The  height  of  the  moun- 
tain, the  diameter  of  the  world,  the  velocity  of  the 
comet,  and  the  distance  between  the  stars,  depend  on  the 
distance  of  each  from  the  point  of  sight.  Every  degree 
is  divided  into  60  minutes  (marked  '),  and  every  minute 
into  60  seconds  (marked  "). 

Imagine  yourself  inside  a  perfect  sphere  one  hundred 
feet  in  diameter,  with  the  interior  surface  above,  around, 
and  below  studded  with  fixed  bright  points  like  stars. 
The  familiar  constellations  of  night  might  be  blazoned 
there  in  due  proportion. 

If  this  star-sprent  sphere  were  made  to  revolve  once 
in  twenty-four  hours,  all  the  stars  would  successively 


60      .  CELESTIAL  MEASUREMENTS. 

pass  in  review.  How  easily  we  could  measure  distances 
between  stars,  from  a  certain  fixed  meridian,  or  the 
equator!  How  easily  we  could  tell  when  any  particular 
star  would  culminate  !  It  is  as  easy  to  take  all  these 
measurements  when  our  earthly  observatory  is  steadi- 
ly revolved  within  the  sphere  of  circumambient  stars. 
Stars  can  be  mapped  as  readily  as  the  streets  of  a  great 
city.  Looking  down  on  it  in  the  night,  one  could  trace 
the  lines  of  lighted  streets,  and  judge  something  of  its 
extent  and  regularity.  But  the  few  lamps  of  even- 
ing would  suggest  little  of  the  greatness  of  the  public 
buildings,  the  magnificent  enterprise  and  commerce  of 
its  citizens,  or  the  intelligence  of  its  scholars.  Looking 
up  to  the  lamps  of  the  celestial  city,  one  can  judge 
something  of  its  extent  and  regularity ;  but  they  sug- 
gest little  of  the  magnificence  of  the  many  mansions. 

Stars  are  reckoned  as  so  many  degrees,  minutes,  and 
seconds  from  each  other,  from  the  zenith,  or  from  a  giv- 
en meridian,  or  from  the  equator.  Thus  the  stars  called 
the  Pointers,  in  the  Great  Bear,  are  5°  apart ;  the  near- 
est one  is  29°  from  the  Pole  Star,  which  is  some  40° 
above  the  horizon  at  Philadelphia.  In  going  to  Eng- 
land you  creep  up  toward  the  north  end  of  the  earth, 
till  the  Pole  Star  is  54°  high.  It  stays  near  its  place 
among  the  stars  continually, 

"Of  whose  true-fixed  and  resting  quality 
There  is  no  fellow  in  the  firmament." 

How  to  Measure. 

Suppose  a  telescope,  fixed  to  a  mural  circle,  to  revolve 
on  an  axis,  as  in  Fig.  21 ;  point  it  horizontally  at  a  star ; 


USES  OF  ASTRONOMY. 


61 


turn  it  up  perpendicular  to  another  star.  Of  course 
the  two  stars  are  90°  apart,  and  the  graduated  scale, 
which  is  attached  to  the  outer  edge  of  the  circle,  shows 
a  revolution  of  a  quarter  circle,  or  90°.  But  a  perfect 
accuracy  of  measurement  must  be  sought ;  for  to  mis- 
take the  breadth  of  a  hair,  seen  at  the  distance  of  one 
hundred  and  twenty-five  feet,  would  cause  an  error  of 
3,000,000  miles  at  the  distance  of  the  sun,  and  iru- 


Fig.  521.— Mural  Circle. 

mensely  more  at  the  distance  of  the  stars.  The  cor- 
rection of  an  inaccuracy  of  no  greater  magnitude  than 
that  has  reduced  our  estimate  of  the  distance  of  our 
sun  3,000,000  miles. 

Consider  the  nicety  of  the  work.  Suppose  the  grad- 
uated scale  to  be  thirty  feet  in  circumference.  Divided 
into  360°,  each  would  be  one  inch  long.  Divide  each 
degree  into  60',  each  one  is  ^  of  an  inch  long.  It  takes 
good  eyesight  to  discern  it.  But  each  minute  must  be 


62  CELESTIAL  MEASUREMENTS. 

divided  into  60",  and  these  must  not  only  be  noted,  but 
even  tenths  and  Irundredths  of  seconds  must  be  discern- 
ed. Of  course  they  are  not  seen  by  the  naked  eye; 
some  mechanical  contrivance  must  be  called  in  to  assist. 
A  watch  loses  two  minutes  a  week,  and  hence  is  unrelia- 
ble. It  is  taken  to  a  watch-maker  that  every  single  sec- 
ond may  be  quickened  -rnrliru  Pai't  of  itself.  Now  YTroinr 
part  of  a  second  would  be  a  small  interval  of  time  to 
measure,  but  it  must  be  under  control.  '  If  the  tempera- 
ture of  a  summer  morning  rises  ten  or  twenty  degrees 
we  scarcely  notice  it ;  but  the  magnetic  tasimeter  meas- 
ures -soVo-  of'  a  degree. 

Come  to  earthly  matters.  In  1874,  after  nearly 
twenty -eight  years'  work,  the  State  of  Massachusetts 
opened  a  tunnel  nearly  five  miles  long  through  the 
Iloosac  Mountains.  In  the  early  part  of  the  work  the 
engineers  sunk  a  shaft  near  the  middle  1028  feet  deep. 
Then  the  question  to  be  settled  was  where  to  go  so  as 
to  meet  the  approaching  excavations  from  the  east  and 
west.  A  compass  could  not  be  relied  on  under  a  moun- 
tain. The  line  must  be  mechanically  fixed.  A  little 
divergence  at  the  starting-point  would  become  so  great, 
miles  away,  that  the  excavations  might  pass  each  other 
without  meeting;  the  grade  must  also  rise  toward  the 
central  shaft,  and  fall  in  working  away  from  it ;  but  the 
lines  were  fixed  with  such  infinitesimal  accuracy  that, 
when  the  one  going  west  from  the  eastern  portal  and 
the  one  going  east  from  the  shaft  met  in  the  heart  of 
the  mountain,  the  western  line  was  only  one-eighth  of 
an  inch  too  high,  and  three-sixteenths  of  an  inch  too  far 
north.  To  reach  this  perfect  result  they  had  to  trian- 
gulate from  the  eastern  portal  to  distant  mountain 


USES  OF  ASTRONOMY. 


63 


peaks,  and  thence  down  the  valley  to  the  central  shaft, 
and  thus  fix  the  direction  of  the  proposed  line  across 
the  mouth  of  the  shaft.  Plumb-lines  were  then  drop- 
ped one  thousand  and  twenty-eight  feet,  and  thus  the 
line  at  the  bottom  was  fixed. 

Three  attempts  were  made— in  1867, 1870,  and  1872 
— to  fix  the  exact  time-distance  between  Greenwich  and 
Washington.  These  three  separate  efforts  do  not  differ 
one-tenth  of  a  second.  Such  demonstrable  results  on 
earth  greatly  increase  our  confidence  in  similar  measure- 
ments in  the  skies. 

A  scale  is  frequently  affixed  to  a  pocket -rule,  by 
which  we  can  easily  measure  one-hundredth  of  an  inch 
(Fig.  22).  The  upper  and  lower  line  is 
divided  into  tenths  of  an  inch.  Ob- 
serve the  slanting  line  at  the  right  hand. 
It  leans  from  the  perpendicular  one- 
tenth  of  an  inch,  as  shown  by  noticing 
where  it  reaches  the  top  line.  When 
it  reaches  the  second  horizontal  line  it 
has  left  the  perpendicular  one-tenth  of  that  tenth — that 
is,  one-hundredth.  The  intersection  marks  -£?&  of  an 
inch  from  one  end,  and  one-hundredth  from  the  other. 

When  division-lines,  on  measures  of  great  nicety,  get 
too  fine  to  be  read  by  the  eye,  we  use  the  microscope. 
By  its  means  we  are  able  to  count  112,000  lines  ruled 
on  a  glass  plate  within  an  inch.  The  smallest  object 
that  can  be  seen  by  a  keen  eye  makes  an  angle  of  40", 
but  by  putting  six  microscopes  on  the  scale  of  the  tel- 
escope on  the  mural  circle,  we  are  able  to  reach  an 
exactness  of  0".l,  or  -g-g-Vo  of  an  inch.  This  instru- 
ment is  used  to  measure  the  declination  of  stars,  or  an- 


Fig.  22. 


G4  CELESTIAL  MEASUREMENTS. 

gular  distance  north  or  south  of  the  equator.  Thus  a 
star's  place  in  two  directions  is  exactly  fixed.  "When 
the  telescope  is  mounted  on  two  pillars  instead  of  the 
face  of  a  wall,  it  is  called  a  transit  instrument.  This 
is  used  to  determine  the  time  of  transit  of  a  star  over 
the  meridian,  and  if  the  transit  instrument  is  provided 
with  a  graduated  circle  it  can  also  be  used  for  the  same 
purposes  as  the  mural  circle.  Man's  capacity  to  meas- 
ure exactly  is  indicated  in  his  ascertainment  of  the 
length  of  waves  of  light.  It  is  easy  to  measure  the 
three  hundred  feet  distance  between  the  crests  of 
storm-waves  in  the  wide  Atlantic ;  easy  to  measure  the 
different  wave-lengths  of  the  different  tones  of  musical 
sounds.  So  men  measure  the  lengths  of  the  undula- 
tions of  light.  The  shortest  is  of  the  violet  light,  154.84 
ten-millionths  of  an  inch.  By  the  horizontal  pendulum 
Professor  Eoot  has  made  rainnnnnF  °^  an  mc^  aPParent- 
The  next  elements  of  accuracy  must  be  perfect  time 
and  perfect  notation  of  time.  As  has  been  said,  we 
get  our  time  from  the  stars.  Thus  the  infinite  and 
heavenly  dominates  the  finite  and  earthly.  Clocks  are 
set  to  the  invariable  sidereal  time.  Sidereal  noon  is 
when  we  have  turned  ourselves  under  the  point  where 
the  sun  crosses  the  equator  in  March,  called  the  vernal 
equinox.  Sidereal  clocks  are  figured  to  indicate  twenty- 
four  hours  in  a  day :  they  tick  exact  seconds.  To  map 
stars  we  wish  to  know  the  exact  second  when  they  cross 
the  meridian,  or  the  north  and  south  line  in  the  celestial 
dome  above  us.  The  telescope  (Fig.  21,  p.  61)  swings  ex- 
actly north  and  south.  In  its  focus  a  set  of  fine  threads 
of  spider-lines  is  placed  (Fig.  23).  The  telescope  is  set 
just  high  enough,  so  that  by  the  rolling  over  of  the  earth 


USES  OF  ASTRONOMY. 


65 


Fig.  -23.— Transit  of  a  Star  noted. 


the  star  will  come  into  the  field  jnst  above  the  horizon- 
tal thread.  The  observer 
notes  the  exact  second  and 
tenth  of  a  second  when  the 
star  reaches  each  vertical 
thread  in  the  instrument, 
adds  together  the  times  and 
divides  by  five  to  get  the 
average,  and  the  exact  time 
is  reached. 

But  man  is  not  reliable 
enough  to  observe  and  record 
with  sufficient  accuracy.  Some,  in  their  excitement,  an- 
ticipate its  positive  passage,  and  some  cannot  get  their 
slow  mental  machinery  in  motion  till  after  it  has  made 
the  transit.  Moreover,  men  fall  into  a  habit  of  esti- 
mating some  numbers  of  tenths  of  a  second  oftener 
than  others.  It  will  be  found  that  a  given  observer 
will  say  three  tenths  or  seven  tenths  oftener  than  four 
or  eight.  He  is  falling  into  ruts,  and  not  trustworthy. 
General  O.  M.  Mitchel.  who  had  been  director  of  the 
Cincinnati  Observatory,  once  told  one  of  his  staff -offi- 
cers that  he  was  late  at  an  appointment.  "  Only  a 
few  minutes,"  said  the  officer,  apologetically.  "Sir," 
said  the  general,  "where  I  have  been  accustomed  to 
work,  hundredths  of  a  second  are  too  important  to  be 
neglected."  And  it  is  to  the  rare  genius  of  this  astron- 
omer, and  to  others,  that  we  owe  the  mechanical  accu- 
racy that  we  now  attain.  The  clock  is  made  to  mark  its 
seconds  on  paper  wrapped  around  a  revolving  cylinder. 
Under  the  observer's  fingers  is  an  electric  key.  This 
he  can  touch  at  the  instant  of  the  transit  of  the  star 


66  CELESTIAL  MEASUREMENTS. 

over  eacli  wire,  and  thus  put  his  observation  on  the  same 
line  between  the  seconds  dotted  by  the  clock.  Of  course 
these  distances  can  be  measured  to  minute  fractional 
parts  of  a  second. 

But  it  has  been  found  that  it  takes  an  appreciable 
time  for  every  observer  to  get  a  thing  into  his  head  and 
out  of  his  finger-ends,  and  it  takes  some  observers  longer 
than  others.  A  dozen  rnen,  seeing  an  electric  spark,  are 
liable  to  bring  down  their  recording  marks  in  a  dozen 
different  places  on  the  revolving  paper.  Hence  the 
time  that  it  takes  for  each  man  to  get  a  thing  into  his 
head  and  out  of  his  fingers  is  ascertained.  This  time  is 
called  his  personal  equation,  and  is  subtracted  from  all 
of  his  observations  in  order  to  get  at  the  true  time;  so 
willing  are  men  to  be  exact  about  material  matters. 
Can  it  be  thought  that  moral  and  spiritual  matters  have 
no  precision?  Thus  distances  east  or  west  from  any 
given  star  or  meridian  are  secured ;  those  north  and 
south  from  the  equator  or  the  zenith  are  as  easily  fixed, 
and  thus  we  make  such  accurate  maps  of  the  heavens 
that  any  movements  in  the  far-off  stars — so  far  that  it 
may  take  centuries  to  render  the  swiftest  movements 
appreciable — may  at  length  be  recognized  and  account- 
ed for. 

We  now  come  to  a  little  study  of  the  modes  of 
measuring  distances.  Create  a  perfect 
square  (Fig.  24);  draw  a  diagonal  line. 
The  square  angles  are  90°,  the  divided 
angles  give  two  of  45°  each.  Now  the 
base  A  B  is  equal  to  the  perpendicu- 


lar A  C.     Now  any  point — C,  where  a  F\S.  24. 

perpendicular,  A  C,  and  a  diagonal,  B  C,  meet — will  be 


USES  OF  ASTRONOMY. 


67 


as  far  from  A  as  B  is.    It  makes  no  difference  if  a  river 

flows  between  A  and  C,  and  we  cannot  go  over  it;  we 

can  measure  its  distance  as  easily  as 

if  we  could.     Set  a  table  four  feet  by  ff/? 

eight  out-doors  (Fig.  25) ;  so  arrange  it  /• 

that,  looking  along  one  end,  the  line  /  « 

of  sight  just  strikes  a  tree  the  other  /    » 

side  of  the  river.     Go  to  the  other 

end,  and,  looking  toward  the  tree,  you 

find  the  line  of  sight  to  the  tree  falls 

an  inch  from  the  end  of  the  table  on 

the  farther  side.    The  lines,  therefore, 

approach  each  other  one  inch  in  every 

four  feet,  and  will  come  together  at  a 

tree  three  hundred  and  eighty -four    ._jii 

feet  away. 

The  next  process  is  to  measure  the  Fig.  25.— Measuring  Dis- 
height  or  magnitude  of  objects  at  an 
ascertained  distance.     Put  two  pins  in  a  stick  half  an 
inch  apart  (Fig.  26).    Hold  it  up  two  feet  from  the  eye, 


Fig.  26.— Measuring  Elevations. 


and  let  the  upper  pin  fall  in  line  with  your  eye  and  the 
top  of  a  distant  church  steeple,  and  the  lower  pin  in 
line  with  the  bottom  of  the  church  and  your  eye.  If 
the  church  is  three-fourths  of  a  mile  away,  it  must  be 
eighty-two  feet  high ;  if  a  mile  away,  it  must  be  one 
hundred  and  ten  feet  high.  For  if  two  lines  spread 


68  CELESTIAL  MEASUREMENTS. 

one-half  an  inch  going  two  feet,  in  going  four  feet  they 
will  spread  an  inch,  and  in  going  a  mile,  or  five  thou- 
sand two  hundred  and  eighty  feet,  they  will  spread  out 
one -fourth  as  many  inches,  viz.,  thirteen  hundred  and 
twenty — that  is,  one  hundred  and  ten  feet.  Of  course 
these  are  not  exact  methods  of  measurement,  and  would 
not  be  correct  to  a  hair  at  one  hundred  and  twenty-five 
feet,  but  they  perfectly  illustrate  the  true  methods  of 
measurement. 

Imagine  a  base  line  ten  inches  long.  At  each  end 
erect  a  perpendicular  line.  If  they  are  carried  to  in- 
finity they  will  never  meet :  will  be  forever  ten  inches 
apart.  But  at  the  distance  of  a  foot  from  the  base  line 
incline  one  line  toward  the  other  TiminnroTr  of  an  inch, 
and  the  lines  will  come  together  at  a  distance  of  three 
hundred  miles.  That  new  angle  differs  from  the  for- 
mer right  angle  almost  intinitesimally,  but  it  may  be 
measured.  Its  value  is  about  three-tenths  of  a  second. 
If  we  lengthen  the  base  line  from  ten  inches  to  all  the 
miles  we  can  command,  of  course  the  point  of  meet- 
ing will  be  proportionally  more  distant.  The  angle 
made  by  the  lines  where  they  come  together  will  be 
obviously  the  same  as  the  angle  of  divergence  from  a 
right  angle  at  this  end.  That  angle  is  called  the  parallax 
of  any  body,  and  is  the  angle  that  would  be  made  by 
two  lines  coming  from  that  body  to  the  two  ends  of 
any  conventional  base,  as  the  semi-diameter  of  the  earth. 
That  that  angle  would  vary  according  to  the  various  dis- 
tances is  easily  seen  by  Fig.  27. 

Let  O  P  be  the  base.  This  would  subtend  a  greater 
angle  seen  from  star  A  than  from  star  E.  Let  B  be  far 
enough  away,  and  O  P  would  become  invisible,  and  B 


USES  OF  ASTRONOMY.  69 

would  have  no  parallax  for  that  base.  Thus  the  moon 
has  a  parallax  of  57'  with  the  semi-equatorial  diameter 
of  the  earth  for  a  base.  And  the  sun  has  a  parallax 
8".85  on  the  same  base.  It  is  not  necessary  to  confine 
ourselves  to  right  angles  in  these  measurements,  for  the 
same  principles  hold  true  in  any  angles.  Now,  suppose 
two  observers  on  the  equator 
should  look  at  the  moon  at  the 
same  instant.  One  is  on  the  top 
of  Cotopaxi,  on  the  west  coast  of 
South  America,  and  one  on  the 
west  coast  of  Africa.  They  are 
90°  apart — half  the  earth's  diam- 
eter between  them.  The  one  on 
Cotopaxi  sees  it  exactly  overhead, 
at  an  angle  of  90°  with  the  earth's 
diameter.  The  one  on  the  coast 
of  Africa  sees  its  angle  with  the 
same  line  to  be  89°  3'—  that  is, 
its  parallax  is  57'.  Try  the  same 

experiment  on  the  sun  farther  away,  as  is  seen  in  Fig. 
27,  and  its  smaller  parallax  is  found  to  be  only  8".85. 

It  is  not  necessary  for  two  observers  to  actually  sta- 
tion themselves  at  two  distant  parts  of  the  earth  in 
order  to  determine  a  parallax.  If  an  observer  could  go 
from  one  end  of  the  base-line  to  the  other,  he  could 
determine  both  angles.  Every  observer  is  actually  car- 
ried along  through  space  by  two  motions :  one  is  that 
of  the  earth's  revolution  of  one  thousand  miles  an  hour 
around  the  axis ;  and  the  other  is  the  movement  of 
the  earth  around  the  sun  of  one  thousand  miles  in  a 
minute.  Hence  we  can  have  the  diameter  not  only  of 


70  CELESTIAL  MEASUREMENTS. 

the  earth  (eight  thousand  miles)  for  a  base-line,  but  the 
diameter  of  the  earth's  orbit  (184,000,000  miles),  or  any 
part  of  it,  for  such  a  base.  Two  observers  at  the  ends 
of  the  earth's  diameter,  looking  at  a  star  at  the  same  in- 
stant, would  find  that  it  made  the  same  angle  at  both 
ends ;  it  has  no  parallax  on  so  short  a  base.  We  must 
seek  a  longer  one.  Observe  a  certain  star  on  the  21st 

o 

of  March ;  then  let  us  traverse  the  realms  of  space  for 
six  months,  at  one  thousand  miles  a  minute.  We  come 
round  in  our  orbit  to  a  point  opposite  where  we  were 
six  months  ago,  with  184,000,000  of  miles  between  the 
points.  Now,  with  this  for  a  base-line,  measure  the  an- 
gles of  the  same  stars :  it  is  the  same  angle.  Sitting 
in  my  study  here,  I  glance  out  of  the  window  and  dis- 
cern separate  bricks,  in  houses  five  hundred  feet  away, 
with  my  unaided  eye ;  they  subtend  a  discernible  an- 
gle. But  one  thousand  feet  away  I  cannot  distinguish 
individual  bricks ;  their  width,  being  only  two  inches, 
does  not  subtend  an  angle  apprehensible  to  my  vision. 
So  at  these  distant  stars  the  earth's  enormous  orbit,  if 
lying  like  a  blazing  ring  in  space,  with  the  world  set  on 
its  edge  like  a  pearl,  and  the  sun  blazing  like  a  diamond 
in  the  centre,  would  all  shrink  to  a  mere  point.  ]S"ot 
quite  to  a  point  from  the  nearest  stars,  or  we  should 
never  be  able  to  measure  the  distance  of  any  of  them. 
Professor  Airy  says  that  our  orbit,  seen  from  the  nearest 
star,  would  be  the  same  as  a  circle  six-tenths  of  an  inch 
in  diameter  seen  at  the  distance  of  a  mile:  it  would 
all  be  hidden  by  a  thread  one-twenty-fifth  of  an  inch  in 
diameter,  held  six  hundred  and  fifty  feet  from  the  eye. 
If  a  straight  line  could  be  drawn  from  a  star,  Sirius  in 
the  east  to  the  star  Vega  in  the  west,  touching  our 


USES  OF  ASTRONOMY.  71 

earth's  orbit  on  one  side,  as  T  K  A  (Fig.  28),  and  a  line 
were    to   be    drawn   six 
months   later  from 

same  stars,  touching  our  B  ~~-^ 

earth's  orbit  on  the  oth-  ^"^"•^n 

erside,asKBT,sucha  Fi--28- 

line  would  not  diverge  sufficiently  from  a  straight  line 
for  us  to  detect  its  divergence.  ^Numerous  vain  at- 
tempts had  been  made,  up  to  the  year  1835,  to  detect 
and  measure  the  angle  of  parallax  by  which  we  could 
rescue  some  one  or  more  of  the  stars  from  the  inconceiv- 
able depths  of  space,  and  ascertain  their  distance  from 
us.  .We  are  ever  impelled  to  triumph  over  what  is  de- 
clared to  be  unconquerable.  There  are  peaks  in  the 
Alps  no  man  has  ever  climbed.  They  are  assaulted 
every  year  by  men  zealous  of  more  worlds  to  conquer. 
So  these  greater  heights  of  the  heavens  have  been  as- 
saulted, till  some  ambitious  spirits  have  outsoared  even 
imagination  by  the  certainties  of  mathematics. 

It  is  obvious  that  if  one  star  were  three  times  as  far 
from  us  as  another,  the  nearer  one  would  seem  to  be 
displaced  by  our  movement  in  our  orbit  three  times  as 
much  as  the  other ;  so,  by  comparing  one  star  with  an- 
other, we  reach  a  ground  of  judgment.  The  ascertain- 
ment of  longitude  at  sea  by  means  of  the  moon  affords 
a  good  illustration.  Along  the  track  where  the  moon 
sails,  nine  bright  stars,  four  planets,  and  the  sun  have 
been  selected.  The  nautical  almanacs  give  the  distance 
of  the  moon  from  these  successive  stars  every  hour  in  the 
night  for  three  years  in  advance.  The  sailor  can  measure 
the  distance  at  any  time  by  his  sextant.  Looking  from 
the  world  at  D  (Fig.  29),  the  distance  of  the  moon  and 


72  CELESTIAL  MEASUREMENTS. 

star  is  A  E,  which  is  given  in  the  almanac.  Looking 
from  C,  the  distance  is  only  B  E,  which  enables  even  the 
uneducated  sailor  to  find  the  distance,  C  D,  on  the  earth, 
or  his  distance  from  Greenwich. 


Fig.  29.— Mode  of  Ascertaining  Longitude. 


So,  by  comparisons  of  the  near  and  far  stars,  the  ap- 
proximate distance  of  a  few  of  them  has  been  deter- 
mined. The  nearest  one  is  the  brightest  star  in  the 
Centaur,  seldom  visible  in  our  northern  latitudes,  which 
has  a  parallax  of  about  one  second.  The  next  nearest  is 
No.  61  in  the  Swan,  or  61  Cygni,  having  a  parallax  of 
0".34:.  Approximate  measurements  have  been  made  on 
Sirius,  Capella,  the  Pole  Star,  etc.,  about  eighteen  in  all. 
The  distances  are  immense :  only  the  swiftest  agents 
can  traverse  them.  If  our  earth  were  suddenly  to  dis- 
solve its  allegiance  to  the  king  of  day,  and  attempt  a 
flight  to  the  North  Star,  and  should  maintain  its  flight 
of  one  thousand  miles  a  minute,  it  would  fly  away  to- 
ward Polaris  for  thousands  upon  thousands  of  years,  till 
a  million  years  had  passed  away,  before  it  reached  that 
northern  dome  of  the  distant  sky,  and  gave  its  new  alle- 
giance to  another  sun.  The  sun  it  had  left  behind  it 
would  gradually  diminish  till  it  was  small  as  Arcturus, 
then  small  as  could  be  discerned  by  the  naked  eye, 
until  at  last  it  would  finally  fade  out  in  utter  darkness 
long  before  the  new  sun  was  reached.  Light  can  trav- 
erse the  distance  around  our  earth  eight  times  in  one 
second.  It  comes  in  eight  minutes  from  the  sun,  but 
it  takes  three  and  a  quarter  years  to  come  from  Alpha 


USES  OF  ASTRONOMY.  73 

Centauri,  seven  and  a  quarter  years  from  61  Cygni,  and 
forty-five  years  from  the  Polar  Star. 

Sometimes  it  happens  that  men  steer  along  a  lee 
shore,  dependent  for  direction  on  Polaris,  that  light- 
house in  the  sky.  Sometimes  it  has  happened  that 
men  have  traversed  great  swamps  by  night  when  that 
star  was  the  light-house  of  freedom.  In  either  case  the 
exigency  of  life  and  liberty  was  provided  for  forty-five 
years  before  by  a  Providence  that  is  divine. 

We  do  not  attempt  to  name  in  miles  these  enormous 
distances ;  we  must  seek  another  yard-stick.  Our  astro- 
nomical unit  and  standard  of  measurement  is  the  dis- 
tance-of  the  earth  from  the  sun  —  92,500,000  miles. 
This  is  the  golden  reed  with  which  we  measure  the 
celestial  city.  Thus,  by  laying  down  our  astronomi- 
cal unit  226,000  times,  we  measure  to  Alpha  Centauri, 
more  than  twenty  millions  of  millions  of  miles.  Doubt- 
less other  suns  are  as  far  from  Alpha  Centauri  and 
each  other  as  that  is  from  ours. 

Stars  are  not  near  or  far  according  to  their  brightness. 
61  Cygni  is  a  telescopic  star,  while  Sirius,  the  brightest 
star  in  the  heavens,  is  twice  as  far  away  from  us.  One 
star  differs  from  another  star  in  intrinsic  glory. 

The  highest  testimonies  to  the  accuracy  of  these  ce- 
lestial observations  are  found  in  the  perfect  predictions 
of  eclipses,  transits  of  planets  over  the  sun,  occultation 
of  stars  by  the  moon,  and  those  statements  of  the  Nau- 
tical Almanac  that  enable  the  sailor  to  know  exactly 
where  he  is  on  the  pathless  ocean  by  the  telling  of  the 
stars :  "  On  the  trackless  ocean  this  book  is  the  mariner's 
trusted  friend  and  counsellor ;  daily  and  nightly  its 
revelations  bring  safety  to  ships  in  all  plirts  of  the 


74  CELESTIAL  MEASUREMENTS. 

world.  It  is  something  more  than  a  mere  book ;  it  is 
an  ever-present  manifestation  of  the  order  and  harmony 
of  the  universe." 

Another  example  of  this  wonderful  accuracy  is  found  in 
tracing  the  asteroids.  Within  200,000,000  or  300,000,000 
miles  from  the  sun,  the  two  hundred  and  one  (Sep- 
tember, 1879,)  minute  bodies  that  have  been  already 
discovered  move  in  paths  very  nearly  the  same — indeed 
two  of  them  traverse  the  same  orbit,  being  one  hundred 
and  eighty  degrees  apart ; — they  look  alike,  yet  the  eye 
of  man  in  a  few  observations  so  determines  the  curve 
of  each  orbit,  that  one  is  never  mistaken  for  another. 
But  astronomy  has  higher  uses  than  fixing  time,  estab- 
lishing landmarks,  and  guiding  the  sailor.  It  greatly 
quickens  and  enlarges  thought,  excites  a  desire  to  know, 
leads  to  the  utmost  exactness,  and  ministers  to  adora- 
tion and  love  of  the  Maker  of  the  innumerable  suns. 


THE  SUN. 

"And  God  made  two  great  lights;  the  greater  light  to  rule  the  day, 
and  the  lesser  light  to  rule  the  night :  he  made  the  stars  also. " — Gen.  i.  16. 


'*  It  is  perceived  that  the  sun  of  the  world,  with  all  its  essence,  which  is 
heat  and  light,  flows  into  every  tree,  and  into  every  shrub  and  flower,  and 
into  every  stone,  mean  as  well  as  precious ;  and  that  every  object  takes 
its  portion  from  this  common  influx,  and  that  the  sun  does  not  divide  its 
light  and  heat,  and  dispense  a  part  to  this  and  a  part  to  that.  It  is  simi- 
lar with  the  sun  of  heaven,  from  which  the  Divjne  love  proceeds  as  heat, 
and  the  Divine  wisdom  as  light;  these  two  flow  into  human  minds,  as 
the  heat  and  light  of  the  sun  of  the  world  into  bodies,  and  vivify  them  ac- 
cording to  the  quality  of  the  minds,  each  of  which  takes  from  the  com- 
mon influx  as  much  as  is  necessary." — SWEDENBORG. 


THE  SUN.  77 


Y. 

THE  SUN. 

SUPPOSE  we  had  stood  on  the  dome  of  Boston  State- 
house  November  9th,  1872,  on  the  night  of  the  great 
conflagration,  and  seen  the  fire  break  out;  seen  the  en- 
gines dash  through  the  streets,  tracking  their  path  by 
their  sparks;  seen  the  fire  encompass  a  whole  block, 
leap  the  streets  on  every  side,  surge  like  the  billows  of 
a  storm-swept  sea ;  seen  great  masses  of  inflammable  gas 
rise  like  dark  clouds  from  an  explosion,  then  take  fire 
in  the  air,  and,  cut  off  from  the  fire  below,  float  like 
argosies  of  flame  in  space.  Suppose  we  had  felt  the 
wind  that  came  surging  from  all  points  of  the  compass 
to  fan  that  conflagration  till  it  was  light  enough  a  mile 
away  to  see  to  read  the  finest  print,  hot  enough  to  de- 
compose the  torrents  of  water  that  were  dashed  on  it, 
making  new  fuel  to  feed  the  flame.  Suppose  we  had 
seen  this  spreading  fire  seize  on  the  whole  city,  extend 
to  its  environs,  and,  feeding  itself  on  the  very  soil,  lick 
up  Worcester  with  its  tongues  of  flame — Albany,  New 
York,  Chicago,  St.  Louis,  Cincinnati — and  crossing  the 
plains  swifter  than  a  prairie  fire,  making  each  peak  of 
the  Kocky  Mountains  hold  up  aloft  a  separate  torch  of 
flame,  and  the  Sierras  whiter  with  heat  than  they  ever 
were  with  snow,  the  waters  of  the  Pacific  resolve  into 
their  constituent  elements  of  oxygen  and  hydrogen,  and 


78  ^   SOLAR  SYSTEM. 

burn  with  unquenchable  fire!  We  withdraw  into  the 
air,  and  see  below  a  world  on  fire.  All  the  prisoned 
powers  have  burst  into  intensest  activity.  Quiet  breezes 
have  become  furious  tempests.  Look  around  this  flam- 
ing globe — on  fire  above,  below,  around — there  is  noth- 
ing but  fire.  Let  it  roll  beneath  us  till  Boston  comes 
round  again.  No  ember  has  yet  cooled,  no  spire  of 
flame  has  shortened,  no  surging  cloud  has  been  quiet- 
ed. Not  only  are  the  mountains  still  in  flame,  but 
other  ranges  burst  up  out  of  the  seething  sea.  There  is 
no  place  of  rest,  no  place  not  tossing  with  raging  flame  ! 
Yet  all  this  is  only  a  feeble  figure  of  the  great  burn- 
ing sun.  It  is  but  the  merest  hint,  a  million  times  too 
insignificant. 

The  sun  appears  small  and  quiet  to  us  because  we  are 
so  far  away.  Seen  from  the  various  planets,  the  rela- 
tive size  of  the  sun  appears  as  in  Fig.  30.  Looked  for 
from  some  of  the  stars  about  us,  the  sun  could  not  be 
seen  at  all.  Indeed,  seen  from  the  earth,  it  is  not  al- 
ways the  same  size,  because  the  distance  is  not  always 
the  same.  If  we  represent  the  size  of  the  sun  by  one 
thousand  on  the  23d  of  September  or  21st  of  March,  it 
would  be  represented  by  nine  hundred  and  sixty-seven 
on  the  1st  of  July,  and  by  one  thousand  and  thirty-four 
on  the  1st  of  January. 

We  sometimes  speak  of  the  sun  as  having  a  diameter 
of  860,000  miles.  We  mean  that  that  is  the  extent  of 
the  body  as  seen  by  the  eye.  But  that  is  a  small  part 
of  its  real  diameter.  So  we  say  the  earth  has  an  equa- 
torial diameter  of  7925£  miles,  and  a  polar  one  of  7899. 
But  the  air  is  as  much  a  part  of  the  earth  as  the  rocks 
are.  The  electric  currents  are  as  much  a  part  of  the 


THE  SUN. 


79 


earth  as  the  ores  and  mountains  they  traverse.  What 
the  diameter  of  the  earth  is,  including  these,  no  man  can 
tell.  We  used  to  say  the  air  extended  forty-five  miles, 
but  we  now  know  that  it  reaches  vastly  farther.  So  of 


.  30.—  Relative  Size  of  Sun  as  seen  from  Different  Planets. 


the  sun,  we  might  almost  say  that  its  diameter  is  infi- 
nite, for  its  light  and  heat  reach  beyond  our  measure- 
ment. Its  living,  throbbing  heart  sends  out  pulsations, 
keeping  all  space  full  of  its  tides  of  living  light. 


80 


A   SOL  Alt  SYSTEM. 


i£.  31.— Zodiacal  Light. 

We  might  say  with  evident  truth  that  the  far-off 
planets  are  a  part  of  the  sun,  since  the  space  they  trav- 
erse is  filled  with  the  power  of  that  controlling  king; 
not  only  with  light,  but  also  with  gravitating  power. 

But  come  to  more  ponderable  matters.     If  we  look 


THE  SUN.  81 

into  our  western  sky  soon  after  sunset,  on  a  clear,  moon- 
less night  in  March  or  April,  we  shall  see  a  dim,  soft 
light,  somewhat  like  the  milky- way,  often  reaching, 
well  defined,  to  the  Pleiades.  It  is  wedge-shaped,  in- 
clined to  the  south,  and  the  smallest  star  can  easily  be 
seen  through  it.  Mairan  and  Cassini  affirm  that  they 
have  seen  sudden  sparkles  and  movements  of  light  in  it. 
All  our  best  tests  show  the  spectrum  of  this  light  to  be 
continuous,  and  therefore  reflected  :  which  indicates  that 
it  is  a  ring  of  small  masses  of  meteoric  matter  surround- 
ing the  sun,  revolving  with  it  and  reflecting  its  light. 
One  bit  of  stone  as  large  as  the  end  of  one's  thumb,  in 
a  cubic  mile,  would  be  enough  to  reflect  what  light  we 
see  looking  through  millions  of  miles  of  it.  Perhaps 
an  eye  sufficiently  keen  and  far  away  would  see  the  sun 
surrounded  by  a  luminous  disk,  as  Saturn  is  -with  his 
rings.  As  it  extends  beyond  the  earth's  orbit,  if  this 
be  measured  as  a  part  of  the  sun,  its  diameter  would 
be  about  200,000,000  miles. 

Come  closer.  When  the  sun  is  covered  by  the  disk 
of  the  moon  at  the  instant  of  total  eclipse,  observers  are 
startled  by  strange  swaying  luminous  banners,  ghostly 
and  weird,  shooting  in  changeful  play  about  the  central 
darkness  (Fig.  32).  These  form  the  corona.  Men  have 
usually  been  too  much  moved  to  describe  them,  and 
have  always  been  incapable  of  drawing  them  in  the 
short  minute  or  two  of  their  continuance.  But  in  1878 
men  travelled  eight  thousand  miles,  coining  and  return- 
ing, in  order  that  they  might  note  the  three  minutes  of 
total  eclipse  in  Colorado.  Each  man  had  his  work  as- 
signed to  him,  and  he  was  drilled  to  attend  to  that  and 
nothing  else.  Improved  instruments  were  put  into  his 


82  A  SOLAR  SYSTEM. 

hands,  so  that  the  sun  was  made  to  do  his  own  drawing 
and  give  his  own  picture  at  consecutive  instants.  Fig. 
33  is  a  copy  of  a  photograph  of  the  corona  of  1878,  by 


Fig.  32.— The  Corona  in  1858,  Brazil. 

Mr.  Henry  Draper.  It  showed  much  less  changeability 
that  year  than  common,  it  being  very  near  the  time  of 
least  sun-spot.  The  previous  picture  was  taken  near  the 
time  of  maximum  sun-spot. 

It  was  then  settled  that  the  corona  consists  of  re- 
flected light,  sent  to  us  from  dust  particles  or  meteor- 
oids  swirling  in  the  vast  seas,  giving  new  densities  and 


THE  SUN.  83 

rarities,  and  hence  this  changeful  light.  "Whether  they 
are  there  by  constant  projection,  and  fall  again  to  the 
sun,  or  are  held  by  electric  influence,  or  by  force  of  or- 
bital revolution,  we  do  not  know.  That  the  corona  can- 
not be  in  any  sense  an  atmosphere  of  any  continuous 
gas,  is  seen  f rom  the  fact  that  the  comet  of  1843,  pass- 
ing within  93,000  miles  of  the  body  of  the  sun,  was  not 
burned  out  of  existence  as  a  comet,  nor  in  any  percepti- 


i£.  33.— The  Corona  iu  1S78,  Colorado. 

ble  degree  retarded  in  its  motion.  If  the  sun's  diameter 
is  to  include  the  corona,  it  will  be  from  1,260,000  to 
1,460,000  miles. 


84  A   SOLAR  SYSTEM. 

Come  closer  still.  At  the  instant  of  the  totality  of 
the  eclipse  red  flames  of  most  fantastic  shape  play  along 
the  edge  of  the  moon's  disk.  They  can  be  seen  at  any 
time  by  the  use  of  a  proper  telescope  with  a  spectro- 
scope attached.  I  have  seen  them  with  great  distinct- 
ness and  brilliancy  with  the  excellent  eleven-inch  tele- 
scope of  the  Wesleyan  University.  A  description  of  their 
appearance  is  best  given  in  the  language  of  Professor 
Young,  of  Princeton  College,  who  has  made  these  flames 
the  object  of  most  successful  study.  On  September 
7th,  1871,  he  was  observing  a  large  hydrogen  cloud  by 
the  sun's  edge.  This  cloud  was  about  100,000  miles 
long,  and  its  upper  side  was  some  50,000  miles  above  the 
sun's  surface,  the  lower  side  some  15,000  miles.  The 
whole  had  the  appearance  of  being  supported  on  pillars 
of  fire,  these  seeming  pillars  being  in  reality  hydrogen 
jets  brighter  and  more  active  than  the  substance  of  the 
cloud.  At  half -past  twelve,  when  Professor  Young 
chanced  to  be  called  away  from  his  observatory,  there 
were  no  indications  of  any  approaching  change,  except 
that  one  of  the  connecting  stems  of  the  southern  extrem- 
ity of  the  cloud  had  grown  considerably  brighter  and 
more  curiously  bent  to  one  side ;  and  near  the  base  of 
another,  at  the  northern  end,  a  little  brilliant  lump  had 
developed  itself,  shaped  much  like  a  summer  thunder- 
head. 

But  when  Professor  Young  returned,  about  half  an 
hour  later,  he  found  that  a  very  wonderful  change  had 
taken  place,  and  that  a  very  remarkable  process  was  act- 
ually in  progress.  "The  whole  thing  had  been  literally 
blown  to  shreds,"  he  says,  "  by  some  inconceivable  up- 
rush  from  beneath.  In  place  of  the  quiet  cloud  I  had 


Fig.  34.— Solar  Prominences  of  Flaming  Hydrogen. 


THE  SUN.  87 

left,  the  air — if  I  may  use  the  expression — was  filled 
with  the  flying  debris,  a  mass  of  detached  vertical  fusi- 
form fragments,  each  from  ten  to  thirty  seconds  (i.  e., 
from  four  thousand  five  hundred  to  thirteen  thousand 
five  hundred  miles)  long,  by  two  or  three  seconds  (nine 
hundred  to  thirteen  hundred  and  fifty  miles)  wide- 
brighter,  and  closer  together  where  the  pillars  had  for- 
merly stood,  and  rapidly  ascending.  When  I  looked, 
some  of  them  had  already  reached  a  height  of  nearly 
four  minutes  (100,000  miles);  and  while  I  watched 
them  they  arose  with  a  motion  almost  perceptible  to 
the  eye,  until,  in  ten  minutes,  the  uppermost  were  more 
than  200,000  miles  above  the  solar  surface.  This  was 
ascertained  by  careful  measurements,  the  mean  of  three 
closely  accordant  determinations  giving  210,000  miles 
as  the  extreme  altitude  attained.  I  am  particular  in 
the  statement,  because,  so  far  as  I  know,  chromato- 
spheric  matter  (red  hydrogen  in  this  case)  has  never 
before  been  observed  at  any  altitude  exceeding  five 
minutes,  or  135,000  miles.  The  velocity  of  ascent,  also 
— one  hundred  and  sixty -seven  miles  per  second — is 
considerably  greater  than  anything  hitherto  recorded. 
*  *  *  As  the  filaments  arose,  they  gradually  faded  away 
like  a  dissolving  cloud,  and  at  a  quarter  past  one  only 
a  few  filmy  wisps,  with  some  brighter  streamers  low 
down  near  the  chromatosphere,  remained  to  mark  the 
place.  But  in  the  mean  while  the  little  '  thunder-head' 
before  alluded  to  had  grown  and  developed  wonder- 
fully into  a  mass  of  rolling  and  ever-changing  flame, 
to  speak  according  to  appearances.  First,  it  was  crowd- 
ed down,  as  it  were,  along  the  solar  surface ;  later,  it 
arose  almost  pyramidally  50,000  miles  in  height ;  then 


88  A   SOLAR  SYSTEM. 

its  suriimit  was  drawn  down  into  long  filaments  and 
threads,  which  were  most  curiously  rolled  backward  and 
forward,  like  the  volutes  of  an  Ionic  capital,  and  finally 
faded  away,  and  by  half-past  two  had  vanished  like  the 
other.  The  whole  phenomenon  suggested  most  forcibly 
the  idea  of  an  explosion  under  the  great  prominence, 
acting  mainly  upward,  but  also  in  all  directions  out- 
ward ;  and  then,  after  an  interval,  followed  by  a  corre- 
sponding in-rush." 

No  language  can  convey  nor  mind  conceive  an  idea 
of  the  fierce  commotion  we  here  contemplate.  If  we 
call  these  movements  hurricanes,  we  must  remember 
that  what  we  use  as  a  figure  moves  but  one  hundred 
miles  an  hour,  while  these  move  one  hundred  miles  a 
second.  Such  storms  of  fire  on  earth,  "  coming  down 
upon  us  from  the  north,  would,  in  thirty  seconds  after 
they  had  crossed  the  St.  Lawrence,  be  in  the  Gulf  of 
Mexico,  carrying  with  them  the  whole  surface  of  the 
continent  in  a  mass  not  simply  of  ruins  but  of  glowing 
vapor,  in  which  the  vapors  arising  from  the  dissolution 
of  the  materials  composing  the  cities  of  Boston,  New 
York,  and  Chicago  would  be  mixed  in  a  single  indis- 
tinguishable cloud."  In  the  presence  of  these  evident 
visions  of  an  actual  body  in  furious  flame,  we  need  hes- 
itate no  longer  in  accepting  as  true  the  words  of  St. 
Peter  of  the  time  "  in  which  the  [atmospheric]  heav- 
ens shall  pass  away  with  a  great  noise,  and  the  ele- 
ments shall  melt  with  fervent  heat ;  the  earth  also,  and 
the  works  that  are  therein,  shall  be  burned  up." 

This  region  of  discontinuous  flame  below  the  corona 
is  called  the  chromosphere.  Hydrogen  is  the  principal 
material  of  its  upper  part ;  iron,  magnesium,  and  other 


THE  SUX.  89 

metals,  soine  of  them  as  yet  unknown  on  earth,  but  hav- 
ing a  record  in  the  spectrum,  in  the  denser  parts  below. 
If  these  fierce  fires  are  a  part  of  the  sun,  as  they  as- 
suredly are,  its  diameter  would  be  from  1,060,000  to 
1,260,000  miles. 

Let  us  approach  even  nearer.  AVe  see  a  clearly  recog- 
nized even  disk,  of  equal  dimensions  in  every  direction. 
This  is  the  photosphere.  We  here  reach  some  definite- 
ly measurable  data  for  estimating  its  visible  size.  We 
already  know  its  distance.  Its  disk  subtends  an  angle 
of  32'  12".6,  or  a  little  more  than  half  a  degree.  Three 
hundred  and  sixty  such  suns,  laid  side  by  side,  would 
span  the  celestial  arch  from  east  to  west  with  a  half 
circle  of  light.  Two  lines  drawn  from  our  earth  at  the 
angle  mentioned  would  be  860,000  miles  apart  at  the 
distance  of  92,500,000  miles.  This.,  then,  is  the  diameter 
of  the  visible  and  measurable  part  of  the  sun.  It  would 
require  one  hundred  and  eight  globes  like  the  earth  in 
a  line  to  measure  the  sun's  diameter,  and  three  hundred 
and  thirty-nine,  to  be  strung  like  the  beads  of  a  neck- 
lace, to  encircle  his  waist.  The  sun  has  a  volume  equal 
to  1.245,000  earths,  but  being  only  one-quarter  as  dense, 
it  has  a  mass  of  only  326.800  earths.  It  has  seven  hun- 
dred times  the  mass  of  all  the  planets,  asteroids,  and 
satellites  put  together.  Thus  it  is  able  to  control  them 
all  by  its  greater  power  of  attraction. 

Concerning  the  condition  of  the  surface  of  the  sun 
many  opinions  are  held.  That  it  is  hot  beyond  all  esti- 
mate is  indubitable.  Whether  solid  or  gaseous  we  are 
not  sure.  Opinions  differ:  some  incline  to  the  first 
theory,  others  to  the  second  ;  some  deem  the  sun  com- 
posed of  solid  particles,  floating  in  gas  so  condensed 


90  A  SOLAR  SYSTEM. 

by  pressure  and  attraction  as  to  shine  like  a  solid.  It 
has  no  sensible  changes  of  general  level,  but  has  pro- 
digious activity  in  spots.  These  spots  have  been  the 
objects  of  earnest  and  almost  hourly  study  on  the  part 
of  such  men  as  Secchi,  Lockyer,  Faye,  Young,  and  oth- 
ers, for  years.  But  it  is  a  long  way  off  to  study  an  ob- 
ject. No  telescope  brings  it  nearer  than  200,000  miles. 
Theory  after  theory  has  been  advanced,  each  one  satis- 
factory in  some  points,  none  in  all.  The  facts  about  the 
spots  are  these :  They  are  most  abundant  on  the  two 
sides  of  the  equator.  They  are  gregarious,  depressed 
below  the  surface,  of  vast  extent,  black  in  the  centre, 
usually  surrounded  by  a  region  of  partial  darkness,  be- 
yond which  is  excessive  light.  They  have  motion  of 
their  own  over  the  surface — motion  rotating  about  an 
axis,  upward  and  downward  about  the  edges.  They 
change  their  apparent  shape  as  the  sun  carries  them 


Fig.  35.— Change  in  Spots  as  rotated  across  the  Disk,  showing  Cavities. 

across  its  disk  by  axial  revolution,  being  narrow  as  they 
present  their  edges  to  us,  and  rounder  as  we  look  per- 
pendicularly into  them  (Fig.  35). 

These  spots  are  also  very  variable  in  number,  some- 
times there  being  none  for  nearly  two  hundred  days,  and 
again  whole  years  during  which  the  sun  is  never  with- 
out them.  The  period  from  maximum  to  maximum 


THE  SUN.  91 

of  spots  is  about  eleven  years.  We  might  look  for 
them  again  and  again  in  vain  this  year  (1878).  They 
will  be  most  numerous  in  1882  and  1893.  The  cause 
of  this  periodicity  was  inferred  to  be  the  near  approach 
of  the  enormous  planet  Jupiter,  causing  disturbance  by 
its  attraction.  But  the  periods  do  not  correspond,  and 
the  cause  is  the  result  of  some  law  of  solar  action  to  us 
as  yet  unknown. 

These  spots  may  be  seen  with  almost  any  telescope, 
the  eye  being  protected  by  deeply  colored  glasses. 

Until  within  one  hundred  years  they  were  supposed 
to  be  islands  of  scoriae  floating  in  the  sea  of  molten 
matter.  But  they  were  depressed  below  the  surface, 
and  showed  a  notch  when  on  the  edge.  Wilson  origi- 
nated and  Herschel  developed  the  theory  that  the  sun's 
real  body  was  dark,  cool,  and  habitable,  and  that  the 
photosphere  was  a  luminous  stratum  at  a  distance  from 
the  real  body,  with  openings  showing  the  dark  spots 
below.  Such  a  sun  would  have  cooled  off  in  a  week, 
but  would  previously  have  annihilated  all  life  below. 

The  solar  spots  being  most  abundant  on  the  two 
sides  of  the  equator,  indicates  their  cyclonic  character; 
the  centre  of  a  cyclone  is  rarefied,  and  therefore  colder, 
and  cold  on  the  sun  is  darkness.  M.  Faye  says :  "  Like 
our  cyclones,  they  are  descending,  as  I  have  proved  by 
a  special  study  of  these  terrestrial  phenomena.  They 
carry  down  into  the  depths  of  the  solar  mass  the  cooler 
materials  of  the  upper  layers,  formed  principally  of 
hydrogen,  and  thus  produce  in  their  centre  a  decided 
extinction  of  light  and  heat  as  long  as  the  gyratory 
movement  continues.  Finally,  the  hydrogen  set  free 
at  the  base  of  the  whirlpool  becomes  reheated  at  this 


92 


A   SOLAR  SYSTEM. 


great  depth,  and  rises  up  tmnultuously  around  the  whirl- 
pool, forming  irregular  jets,  which  appear  above  the 
chromosphere.  These  jets  constitute  the  protuberances. 
The  whirlpools  of  the  sun,  like  those  on  the  earth,  are 
of  all  dimensions,  from  the  scarcely  visible  pores  to  the 
enormous  spots  which  we  see  from  time  to  time.  They 


Fig.  36.— Solar  Spot,  by  Langley. 

have,  like  those  of  the  earth,  a  marked  tendency,  first  to 
increase  and  then  to  break  up,  and  thus  form  a  row  of 
spots  extending  along  the  same  parallel." 

A  spot  of  20,000  miles  diameter  is  quite  small ;  there 
was  one  74,816  miles  across,  visible  to  the  naked  eye 
for  a  week  in  1843.  This  particular  sun-spot  somewhat 


THE  SUN.  93 

helped  the  Millerites.  On  the  day  of  the  eclipse,  in 
1858,  a  spot  over  107,000  miles  in  extent  was  clearly 
seen.  In  such  vast  tempests,  if  there  were  ships  built 
as  large  as  the  whole  earth,  they  would  be  tossed  like 
autumn  leaves  in  an  ocean  storm. 

The  revolution  of  the  sun  carries  a  spot  across  its 
face  in  about  fourteen  days.  After  a  lapse  of  as 
much  more  time,  they  often  reappear  on  the  other  side, 
changed  but  recognizable.  They  often  break  out  or 
disappear  under  the  eye  of  the  observer.  They  divide 
like  a  piece  of  ice  dropped  on  a  frozen  pond,  the  pieces 
sliding  off  in  every  direction,  or  combine  like  separate 
floes  driven  together  into  a  pack.  Sometimes  a  spot 
will  last  for  more  than  two  hundred  days,  recognizable 
through  six  or  eight  revolutions.  Sometimes  a  spot 
will  last  only  half  an  hour. 

The  velocities  indicated  by  these  movements  are  in- 
credible. An  up-rush  and  down-rush  at  the  sides  has 
been  measured  of  twenty  miles  a  second  ;  a  side-rush  or 
whirl,  of  one  hundred  and  twenty  miles  a  second.  These 
tempests  rage  from  a  few  days  to  half  a  year,  traversing 
regions  so  wide  that  our  Indian  Ocean,  the  realm  of 
storms,  is  too  small  to  be  used  for  comparison ;  then, 
as  they  cease,  the  advancing  sides  of  the  spots  approach 
each  other  at  the  rate  of  20,000  miles  an  hour;  they 
strike  together,  and  the  rising  spray  of  fire  leaps  thou- 
sands of  miles  into  space.  It  falls  again  into  the  in- 
candescent surge,  rolls  over  mountains  as  the  sea  over 
pebbles,  and  all  this  for  eon  after  eon  without  sign  of 
exhaustion  or  diminution.  All  these  swift  succeeding 
Himalayas  of  lire,  where  one  hundred  worlds  could  be 
buried,  do  not  usually  prevent  the  sun's  appearing  to 
our  far-off  eyes  as  a  perfect  sphere. 


94  A  SOLAR  SYSTEM. 

What  the  Sun  does  for  us. 

To  what  end  does  this  enormous  power,  this  central 
source  of  power,  exist?  That  it  could  keep  all  these 
gigantic  forces  within  itself  could  not  be  expected.  It 
is  in  a  system  where  every  atom  is  made  to  affect  every 
other  atom,  and  every  world  to  influence  every  other. 
The  Author  of  all  lives  only  to  do  good,  to  send  rain 
on  the  just  and  unjust,  to  cause  his  sun  to  rise  on  the 
evil  and  the  good,  and  to  give  his  spirit,  like  a  perpet- 
ually widening  river,  to  every  man  to  profit  withal. 

The  sun  reaches  his  unrelaxing  hand  of  gravitation 
to  every  other  world  at  every  instant.  The  tendency 
of  every  world  is  to  fly  off  in  a  straight  line.  This  ten- 
dency must  be  momentarily  curbed,  and  the  planet  held 
in  its  true  curve  about  the  sun.  These  giant  worlds 
must  be  perfectly  handled.  Their  speed,  amounting  to 
seventy  times  as  fast  as  that  of  a  rifle -ball,  must  be 
managed.  Each  and  every  world  ma}7  be  said  to  be 
lifted  momentarily  and  swung  perpetually  at  arm's- 
length  by  the  power  of  the  sun. 

The  sun  warms  us.  It  would  convey  but  a  small 
idea  of  the  truth  to  state  how  many  hundreds  of  mill- 
ions of  cubic  miles  of  ice  could  be  melted  by  the  sun 
every  second  without  quenching  its  heat;  but,  if  any 
one  has  any  curiosity  to  know,  it  is  287,200,000  cubic 
miles  of  ice  per  second. 

We  journey  through  space  which  has  a  temperature 
of  200°  below  zero ;  but  we  live,  as  it  were,  in  a  con- 
servatory, in  the  midst  of  perpetual  winter.  We  are 
roofed  over  by  the  air  that  treasures  the  heat,  floored 
under  by  strata  both  absorptive  and  retentive  of  heat, 


THE  SUN.  95 

and  between  the  earth  and  air  violets  grow  and  grains 
ripen.  The  sun  has  a  strange  chemical  power.  It 
kisses  the  cold  earth,  and  it  blushes  with  flowers  and 
matures  the  fruit  and  grain.  We  are  feeble  creatures, 
and  the  sun  gives  us  force.  By  it  the  light  winds  move 
one-eighth  of  a  mile  an  hour,  the  storm  tifty  miles,  the 
hurricane  one  hundred.  The  force  is  as  the  square  of 
the  velocity.  It  is  by  means  of  the  sun  that  the  mer- 
chant's white-sailed  ships  are  blown  safely  home.  So 
the  sun  carries  off  the  miasma  of  the  marsh,  the  pollu- 
tion of  cities,  and  then  sends  the  winds  to  wash  and 
cleanse  themselves  in  the  sea-spray.  The  water-falls  of 
the  earth  turn  machinery,  and  make  Lowells  and  Man- 
chesters  possible,  because  the  sun  lifted  all  that  water 
to  the  hills. 

Intermingled  with  these  currents  of  air  are  the  cur- 
rents of  electric  power,  all  derived  from  the  sun.  These 
have  shown  their  swiftness  and  willingness  to  serve 
man.  The  sun's  constant  force  displayed  on  the  earth 
is  equal  to  543,000,000,000  engines  of  400-horse  power 
each,  working  day  and  night;  and  yet  the  earth  receives 
onbT  2  3  s  i  0*0  o  o  o  o  Part  of  the  whole  force  of  the  sun. 

Besides  all  this,  the  sun,  with  provident  care,  has 
made  and  given  to  us  coal.  This  omnipotent  worker 
has  stored  away  in  past  ages  an  inexhaustible  reservoir 
of  his  power  which  man  may  easily  mine  and  direct, 
thus  releasing  himself  from  absorbing  toil. 

EXPERIMENTS. 

Any  one  may  see  the  spots  on  the  sun  who  has  a  spy-glass.  Darken 
the  room  and  put  the  glass  through  an  opening  toward  the  sun,  as  shown 
in  Fig.  37.  The  eye-piece  should  be  drawn  out  about  half  an  inch  be- 


96 


A   SOLAR  SYSTEM. 


yond  its  usual  focusing  for  distant  objects.     The  farther  it  is  drawn,  the 
nearer  must  \ve  hold  the  screen  for  a  perfect  image. 

By  holding  a  paper  near  the  eye-piece,  the  proper  direction  of  the  instru- 
ment may  be  discovered  without  injury  to  the  eyes.  By  this  means  the 
sun  can  be  studied  from  day  to  day,  and  its  spots  or  the  transits  of  Mer- 
cury and  Venus  shown  to  any  number  of  spectators. 


Fig.  37.— Holding  Telescope  to  see  the  Sim's  Spots. 

First  covering  the  eyes  with  very  dark  or  smoked  glasses,  erect  a  disk 
of  pasteboard  four  inches  in  diameter  between  you  and  the  sun ;  close 
one  eye;  stand  near  it,  and  the  whole  sun  is  obscured.  Withdraw  from 
it  till  the  sun's  rays  just  shoot  over  the  edge  of  the  disk  on  every  side. 
Measure  the  distance  from  the  eye  to  the  disk.  You  will  be  able  to  de- 
termine the  distance  of  the  sun  by  the  rule  of  three:  thus,  as  four  inches 
is  to  860,000  miles,  so  is  distance  from  eye  to  disk  to  distance  from  disk 
to  the  sun.  Take  such  measurements  at  sunrise,  noon,  and  sunset,  and 
see  the  apparently  differing  sizes  due  to  refraction. 


VI, 

THE  PLANETS,  AS   SEEN  FROM  SPACE. 

"He  hangeth  the  earth  upon  nothing." — Job  xxvi.  7. 

5 


"Let  a  power  be  delegated  to  a  finite  spirit  equal  to  the  projection  of 
the  most  ponderous  planet  in  its  orbit,  and,  from  an  exhaustless  magazine, 
let  this  spirit  select  his  grand  central  orb.  Let  him  with  puissant  arm 
locate  it  in  space,  and,  obedient  to  his  mandate,  there  let  it  remain  forever 
fixed.  He  proceeds  to  select  his  planetary  globes,  which  he  is  now  re- 
quired to  marshal  in  their  appropriate  order  of  distance  from  the  sun. 
Heed  well  this  distribution ;  for  should  a  single  globe  be  misplaced,  the 
divine  harmony  is  destroyed  forever.  Let  us  admit  that  finite  intelligence 
mav  at  length  determine  the  order  of  combination ;  the  mighty  host  is 
arrayed  in  order.  These  worlds,  like  fiery  coursers,  stand  waiting  the 
command  to  fly.  But,  mighty  spirit,  heed  well  the  grand  step,  ponder 
well  the  direction  in  which  thou  wilt  launch  each  waiting  world ;  weigh 
well  the  mighty  impulse  soon  to  be  given,  for  out  of  the  myriads  of  direc- 
tions, and  the  myriads  of  impulsive  forces,  there  comes  but  a  single  com- 
bination that  will  secure  the  perpetuity  of  your  complex  scheme.  In  vain 
does  the  bewildered  finite  spirit  attempt  to  fathom  this  mighty  depth.  In 
vain  does  it  seek  to  resolve  the  stupendous  problem.  It  turns  away,  and 
while  endued  with  omnipotent  power,  exclaims,  '  Give  to  me  infinite  wis- 
dom, or  relieve  me  from  the  impossible  task!'" — O.  M.  MITCHEL,  LL.D. 


THE  PLANETS,  AS  SEEN  FROM  SPACE.  99 


VI. 

THE  PLANETS,  AS  SEEN  FROM  SPACE. 

IF  we  were  to  go  out  into  space  a  few  millions  of 
miles  from  either  pole  of  the  sun,  and  were  endowed 
with  wonderful  keenness  of  vision,  we  should  perceive 
certain  facts,  viz :  That  space  is  frightfully  dark  except 
when  we  look  directly  at  some  luminous  body.  There 
is  no  air  to  bend  the  light  out  of  its  course,  no  clouds 
or  other  objects  to  reflect  it  in  a  thousand  directions. 
Every  star  is  a  brilliant  point,  even  in  perpetual  sun- 
shine. The  cold  is  frightful  beyond  the  endurance  of 
our  bodies.  There  is  no  sound  of  voice  in  the  absence 
of  air,  and  conversation  by  means  of  vocal  organs  being 
impossible,  it  must  be  carried  on  by  means  of  mind 
communication.  We  see  below  an  unrevolving  point 
on  the  sun  that  marks  its  pole.  Ranged  round  in  order 
are  the  various  planets,  each  with  its  axis  pointing  in 
very  nearly  the  same  direction.  All  planets,  except  pos- 
sibly Venus,  and  all  moons  except  those  of  Uranus  and 
Neptune,  present  their  equators  to  the  sun.  The  direc- 
tion of  orbital  and  axial  revolution  seen  from  above  the 
North  Pole  would  be  opposite  to  that  of  the  hands  of  a 
watch. 

The  speed  of  this  orbital  revolution  must  be  propor- 
tioned to  the  distance  from  the  sun.  The  attraction  oi 
the  sun  varies  inversely  as  the  square  of  the  distance. 


100 


A   SOLAR  SYSTEM. 


Fig.  38.— Orbits  and  Comparative  Sizes  of  the  Planets. 

It  holds  a  planet  with  a  certain  power ;  one  twice  as  far 
off,  with  one-fourth  that  power.  This  attraction  must  be 
counterbalanced  by  centrifugal  force ;  great  force  from 
great  speed  when  attraction  is  great,  and  small  from  less 


THE  PLANETS,  AS  SEEN  FROM  SPACE.  101 

speed  when  attractive  power  is  diminished  by  distance. 
Hence  Mercury  must  go  29.5  miles  per  second — seven- 
ty times  as  fast  as  a  rifle-ball  that  goes  two-fifths  of  a 
mile  in  a  second — or  be  drawn  into  the  sun;  while 
Neptune,  seventy -five  times  as  far  off,  and  hence  at- 
tracted only  3-5^  as  much,  must  be  slowed  down  to  3.4 
miles  a  second  to  prevent  its  flying  away  from  the  fee- 
bler attraction  of  the  sun.  The  orbital  velocity  of  the 
various  planets  in  miles  per  second  is  as  follows : 


Mercury 29.55 

Venus 21.61 

Earth 18.38 

Mars...,  ..  14.90 


Jupiter 8.06 

Saturn 5.95 

Uranus 4.20 

Neptune 3.36 


Hence,  while  the  earth  makes  one  revolution  in  its 
year,  Mercury  has  made  over  four  revolutions,  or  pass- 
ed through  four  years ;  the  slower  Neptune  has  made 
only  y^f  of  one  revolution. 

The  time  of  axial  rotation  which  determines  the 
length  of  the  day  varies  with  different  planets.  The 
periods  of  the  four  planets  nearest  the  sun  vary  only 
half  an  hour  from  that  of  the  earth,  while  the  enor- 
mous bodies  of  Jupiter  and  Saturn  revolve  in  ten  and 
ten  and  a  quarter  hours  respectively.  This  high  rate  of 
speed,  and  its  resultant,  centrifugal  force,  has  aided  in 
preventing  these  bodies  from  becoming  as  dense  as  they 
would  otherwise  be — Jupiter  being  only  0.24  as  dense  as 
the  earth,  and  Saturn  only  0.13.  This  extremely  rapid 
revolution  produces  a  great  flattening  at  the  poles.  If 
Jupiter  should  rotate  four  times  more  rapidly  than  it 
does,  it  could  not  be  held  together  compactly.  As  it  is, 
the  polar  diameter  is  five  thousand  miles  less  than  the 
equatorial :  the  difference  in  diameters  produced  by  the 


102  A   SOLAR  SYSTEM. 

same  cause  on  the  earth,  owing  to  the  slower  motion 
and  smaller  mass,  being  only  twenty -six  miles.  The 
effect  of  this  will  be  more  specifically  treated  here- 
after. 

The  difference  in  the  size  of  the  planets  is  very  -no- 
ticeable. If  we  represent  the  sun  by  a  gilded  globe 
two  feet  in  diameter,  we  must  represent  Vulcan  and 
Mercury  by  mustard-seeds;  Venus,  by  a  pea  ;  Earth,  by 
another ;  Mars,  by  one-half  the  size ;  Asteroids,  by  the 
motes  in  a  sunbeam ;  Jupiter,  by  a  small-sized  orange ; 
Saturn,  by  a  smaller  one ;  Uranus,  by  a  cherry ;  and 
Neptune,  by  one  a  little  larger. 

Apply  the  principle  that  attraction  is  in  proportion 
to  the  mass,  and  a  man  who  weighs  one  hundred  and 
fifty  pounds  on  the  earth  weighs  three  hundred  and 
ninety-six  on  Jupiter,  and  only  fifty-eight  on  Mars; 
while  on  the  Asteroids  he  could  play  with  bowlders  for 
marbles,  hurl  hills  like  Milton's  angels,  leap  into  the 
fifth- story  windows  with  ease,  tumble  over  precipices 
without  harm,  and  go  around  the  little  worlds  in  seven 
jumps. 

The  seasons  of  a  planet  are  caused  by  the  inclination 
of  its  axis  to  the  plane  of  its  orbit.  In  Fig.  39  the  ro- 
tating earth  is  seen  at  A,  with  its  northern  pole  turning 
in  constant  sunlight,  and  its  southern  pole  in  constant 
darkness ;  everywhere  south  of  the  equator  is  more  dark- 
ness than  day,  and  hence  winter.  Passing  on  to  B,  the 
world  is  seen  illum'inated  equally  on  each  side  of  the 
equator.  Every  place  has  its  twelve  hours'  darkness 
and  light  at  each  revolution.  But  at  C — the  axis  of  the 
earth  always  preserving  the  same  direction — the  north- 
ern pole  is  shrouded  in  continual  gloom.  Every  place 


THE  PLANETS,  AS  SEEN  FROM  SPACE.          105 

north  of  the  equator  gets  more  darkness  than  light,  and 
hence  winter. 

The  varying  inclination  of  the  axes  of  the  different 
planets  gives  a  wonderful  variety  to  their  seasons.  The 
sun  is  always  nearly  over  the  equator  of  Jupiter,  and 
every  place  has  nearly  its  five  hours  day  and  five  hours 
night.  The  seasons  of  Earth,  Mars,  and  Saturn  are  so 
much  alike,  except  in  length,  that  no  comment  is  nec- 
essary. The  ice-fields  at  either  pole  of  Mars  are  ob- 
served to  enlarge  and  contract,  according  as  it  is  win- 
ter or  summer  there.  Saturn's  seasons  are  each  seven 
and  a  half  years  long.  The  alternate  darkness  and  light 
at  the  poles  is  fifteen  years  long. 

But  the  seasons  of  Venus  present  the  greatest  anom- 
aly, if  its  assigned  inclination  of  axis  (75°)  can  be  relied 
on  as  correct,  which  is  doubtful.  Its  tropic  zone  extends 
nearly  to  the  pole,  and  at  the  same  time  the  winter  at 
the  other  pole  reaches  the  equator.  The  short  period 
of  this  planet  causes  it  to  present  the  south  pole  to  the 
sun  only  one  hundred  and  twelve  days  after  it  has  been 
scorching  the  one  at  the  north.  This  gives  two  win- 
ters, springs,  summers,  and  autumns  to  the  equator  in 
two  hundred  and  twenty-five  days. 

If  each  whirling  world  should  leave  behind  it  a  trail 
of  light  to  mark  its  orbit,  and  our  perceptions  of  form 
were  sufficiently  acute,  we  should  see  that  these  curves 
of  light  are  not  exact  circles,  but  a  little  flattened  into 
an  ellipse,  with  the  sun  always  in  one  of  the  foci.  Hence 
each  planet  is  nearer  to  the  sun  at  one  part  of  its  orbit 
than  another;  that  point  is  called  the  perihelion,  and 
the  farthest  point  aphelion.  This  eccentricity  of  orbit, 
or  distance  of  the  sun  from  the  centre,  is  very  small. 


106  A   SOLAR  SYSTEM. 

In  the  case  of  Venus  it  is  only  .007  of  the  whole,  and  in 
no  instance  is  it  more  than  .2,  viz.,  that  of  Mercury.  This 
makes  the  sun  appear  twice  as  large,  bright,  and  hot  as 
seen  and  felt  on  Mercury  at  its  perihelion  than  at  its 
aphelion.  The  earth  is  3,236,000  miles  nearer  to  the 
sun  in  our  winter  than  summer.  Hence  the  summer  in 
the  southern  hemisphere  is  more  intolerable  than  in  the 
northern.  But  this  eccentricity  is  steadily  diminishing 
at  a  uniform  rate,  by  reason  of  the  perturbing  influence 
of  the  other  planets.  In  the  case  of  some  other  planets 
it  is  steadily  increasing,  and,  if  it  were  to  go  on  a  suffi- 
cient time,  might  cause  frightful  extremes  of  tempera- 
ture; but  Lalande  has  shown  that  there  are  limits  at 
which  it  is  said,  "  Thus  far  shalt  thou  go,  and  no  far- 
ther." Then  a  compensative  diminution  will  follow. 

Conceive  a  large  globe,  to  represent  the  sun,  float- 
ing in  a  round  pond.  The  axis  will  be  inclined  7^°  to 
the  surface  of  the  water,  one  side  of  the  equator  be  7-J° 
below  the  surface,  and  the  other  side  the  same  distance 
above.  Let  the  half -sub  merged  earth  sail  around  the 
sun  in  an  appropriate  orbit.  The  surface  of  the  water 
will  be  the  plane  of  the  orbit,  and  the  water  that  reaches 
out  to  the  shore,  where  the  stars  would  be  set,  will  be 
the  plane  of  the  ecliptic.  It  is  the  plane  of  the  earth's 
orbit  extended  to  the  stars. 

The  orbits  of  all  the  planets  do  not  lie  in  the  same 
plane,  but  are  differently  inclined  to  the  plane  of  the 
ecliptic,  or  the  plane  of  the  earth's  orbit.  Going  out 
from  the  sun's  equator,  so  as  to  see  all  the  orbits  of  the 
planets  on  the  edge,  we  should  see  them  inclined  to  that 
of  the  earth,  as  in  Fig.  40. 

If  the  earth,  and  Saturn,  and  Pallas  were  lying  at 


THE  PLANETS,  AS  SEEN  FROM  SPACE. 


107 


Fig.  40.— luclination  of  the  Planes  of  Orbits. 


right  angles  with  the  nodal  line  of  their  orbits,  and  in 
the  same  direction  from  the  sun,  and  the  outer  bodies 
were  to  start  in  a  direct  line  for  the  snn,  they  would 
not  collide  with  the  earth  on  their  way ;  but  Saturn 
would  pass  4,000,000  and  Pallas  50,000,000  miles  over 
our  heads.  From  this  same  cause  we  do  not  see  Yenus 
and  Mercury  make  a  transit  across  the  disk  of  the  sun 
at  every  revolution. 

Fig.  41  shows  a  view  of  the  orbits  of  the  earth  and 


Fig.  41.— Inclination  of  Orbits  of  Venus  and  Earth.    Nodal  Line,  D  B. 

Yenus  seen  not  from  the  edge  but  from  a  position 
somewhat  above.  The  point  E,  where  Yenus  crosses 
the  plane  of  the  earth's  orbit,  is  called  the  ascending 
node.  If  the  earth  were  at  B  when  Yenus  is  at  E, 
Yenus  would  be  seen  on  the  disk  of  the  sun,  making  a 
transit.  The  same  would  be  true  if  the  earth  were  at 
D,  and  Yenus  at  the  descending  node  F. 

This  general  view  of  the  flying  spheres  is  full  of  in- 


108  A   SOLAR  SYSTEM. 

terest.  While  quivering  themselves  with  thunderous 
noises,  all  is  silent  about  them  ;  earthquakes  may  be 
struggling  on  their  surfaces,  but  there  is  no  hint  of 
contention  in  the  quiet  of  space.  They  are  too  distant 
from  one  another  to  exchange  signals,  except,  perhaps, 
the  fleet  of  asteroids  that  sail  the  azure  between  Mars 
and  Jupiter.  Some  of  these  come  near  together,  con- 
tinuing to  fill  each  other's  sky  for  days  with  brightness, 
then  one  gradually  draws  ahead.  They  have  all  phases 
for  each  other — crescent,  half,  full,  and  gibbous.  These 
hundreds  of  bodies  fill  the  realm  where  they  are  with 
inexhaustible  variety.  Beyond  are  vast  spaces — cold, 
dark,  void  of  matter,  but  full  of  power.  Occasionally  a 
little  spark  of  light  looms  up  rapidly  into  a  world  so 
huge  that  a  thousand  of  our  earths  could  not  occupy  its 
vast  bulk.  It  swings  its  four  or  eight  moons  with  per- 
fect skill  and  infinite  strength ;  but  they  go  by  and 
leave  the  silence  unbroken,  the  darkness  unlighted  for 
years.  Nevertheless,  every  part  of  space  is  full  of  pow- 
er. Nowhere  in  its  wide  orbit  can  a  world  find  a  place ; 
at  no  time  in  its  eons  of  flight  can  it  find  an  instant 
when  the  sun  does  not  hold  it  in  safety  and  life. 

The  Outlook  from  the  Earth. 

If  we  come  in  from  our  wanderings  in  space  and 
take  an  outlook  from  the  earth,  we  shall  observe  certain 
movements,  easily  interpreted  now  that  we  know  the 
system,  but  nearly  inexplicable  to  men  who  naturally 
supposed  that  the  earth  was  the  largest,  most  stable, 
and  central  body  in  the  universe. 

We  see,  first  of  all,  sun,  moon,  and  stars  rise  in  the 
east,  mount  the  heavens,  and  set  in  the  west.  As  I 


THE  PLANETS,  AS  SEEN  FROM  SPACE.  109 

revolve  in  my  pivoted  study-chair,  and  see  all  sides  of 
the  room  —  library,  maps,  photographs,  telescope,  and 
windows — I  have  no  suspicion  that  it  is  the  room  that 
whirls ;  but  looking  out  of  a  car-window  in  a  depot  at 
another  car,  one  cannot  tell  which  is  moving,  whether 
it  be  his  car  or  the  other.  In  regard  to  the  world,  we 
have  come  to  feel  its  whirl.  We  have  noticed  the  pyr- 
amids of  Egypt  lifted  to  hide  the  sun ;  the  mountains 
of  Hymettus  hurled  down,  so  as  to  disclose  the  moon 
that  was  behind  them  to  the  watchers  on  the  Acropo- 
lis ;  and  the  mighty  mountains  of  Moab  removed  to  re- 
veal the  stars  of  the  east.  Train  the  telescope  on  any 
star;  it  must  be  moved  frequently,  or  the  world  will 
roll  the  instrument  away  from  the  object.  Suspend  a 
cannon-ball  by  a  fine  wire  at  the  equator ;  set  it  vibrat- 
ing north  and  south,  and  it  swings  all  day  in  precisely 
the  same  direction.  But  suspend  it  directly  over  the 
north  pole,  and  set  it  swinging  toward  Washington  ;  in 
five  hours  after  it  is  swinging  toward  the  Sandwich  Isl- 
ands; in  twelve  hours,  toward  Siam,in  Asia;  in  eighteen 
hours,  toward  Rome,  in  Italy ;  and  in  twenty-four,  to- 
ward Washington  again,  not  because  it  has  changed  the 
plane  of  its  vibration,  but  because  the  earth  has  whirled 
beneath  it,  and  the  torsion  of  the  wire  has  not  been  suf- 
ficient to  compel  the  plane  of  the  original  direction  to 
change  with  the  turning  of  the  earth.  The  law  of  in- 
ertia keeps  it  moving  in  the  same  direction.  The  same 
experimental  proof  of  revolution  is  shown  in  a  propor- 
tional degree  at  any  point  between  the  pole  and  the 
equator. 

But  the  watchers  on  the  Acropolis  do  not  get  turned 
over  so  as  to  see  the  moon  at  the  same  time  every  night. 


110  A   SOLAR  SYSTEM. 

We  turn  down  our  eastern  horizon,  but  we  do  not  find 
fair  Luna  at  the  same  moment  we  did  the  night  before. 
We  are  obliged  to  roll  on  for  some  thirty  to  fifty  min- 
utes longer  before  we  find  the  moon.  It  must  be  go- 
ing in  the  same  direction,  and  it  takes  us  longer  to  get 
round  to  it  than  if  it  were  always  in  the  same  spot  ;  so 
we  notice  a  star  near  the  moon  one  night  —  it  is  13°  west 
of  the  moon  the  next  night.  The  moon  is  going  around 

ii 


*  *  *  *+*  *     *     »      «• 

»  »  » 

•* 


+ 
f 
^ 


v 


*  * 

+ 


Fig.  42.— Showing  the  Sun's  Movement  among  the  Stars. 

the  earth  from  west  to  east,  and  if  it  goes  13°  in  one 
day,  it  will  take  a  little  more  than  twenty-seven  days  to 
go  the  entire  circle  of  360°. 


THE  PLANETS,  AS  SEEN  FROM  SPACE.  Ill 

In  our  outlook  we  soon  observe  that  we  do  not 
by  our  revolution  come  to  see  the  same  stars  rise  at 
the  same  hour  every  night.  Orion  and  the  Pleiades, 
our  familiar  friends  in  the  winter  heavens,  are  gone 
from  the  summer  sky.  Have  they  fled,  or  are  we 
turned  from  them  ?  This  is  easily  understood  from 
Fig.  42. 

When  the  observer  on  the  earth  at  A  looks  into  the 
midnight  sky  he  sees  the  stars  at  E;  but  as  the  earth 
passes  on  to  B,  he  sees  those  stars  at  E  four  minutes 
sooner  every  night ;  and  at  midnight  the  stars  at  F  are 
over  his  head.  Thus  in  a  year,  by  going  around  the  sun, 
we  have  every  star  of  the  celestial  dome  in  our  mid- 
night sky.  "We  see  also  how  the  sun  appears  among 
the  successive  constellations.  When  we  are  at  A,  we 
see  the  sun  among  the  stars  at  G ;  but  as  we  move  to- 
ward B,  the  sun  appears  to  move  toward  H.  If  we 
had  observed  the  sun  rise  on  the  20th  of  August,  18T6, 
we  should  have  seen  it  rise  a  little  before  Regulus, 
and  a  little  south  of  it,  in  such  a  relation  as  circle  1  is 
to  the  star  in  Fig.  43.  By  sunset  the  earth 
had  moved  enough  to  make  the  sun  appear  to 
be  at  circle  2,  and  by  the  next  morning  at  cir- 
cle 3,  at  which  time  Regulus  would  rise  before 
the  sun.  Thus  the  earth's  motion  seems  to 
make  the  sun  traverse  a  regular  circle  among  the  stars 
once  a  year :  but  it  is  not  the  sun  that  moves. 

There  are  certain  stars  that  have  such  irregular,  un- 
certain, vagarious  ways  that  they  were  called  vagabonds, 
or  planets,  by  the  early  astronomers.  Here  is  the  path 
of  Jupiter  in  the  year  1866  (Fig.  44).  These  bodies 
go  forward  for  awhile,  then  stop,  start  aside,  then  retro- 


112  A   SOLAR  SYSTEM. 

grade,  and  go  on  again.     Some  are  never  seen  far  from 
the  sun,  and  others  in  all  parts  of  the  ecliptic. 


Pig.  44. 

First  see  them  as  they  stand  to-day,  as  in  Fig.  45. 
The  observer  stands  on  the  earth  at  A.  It  has  rolled 
over  so  far  that  he  cannot  see  the  sun  ;  it  has  set.  But 


Fig.  45 — Showing  Position  of  Planets. 

Yenus  is  still  in  sight;  Jupiter  is  45°  behind  Yenus, 
and  Saturn  is  seen  90°  farther  east.  When  A  has  roll- 
ed a  little  farther,  if  he  is  awake,  he  will  see  Mars  be- 
fore he  sees  the  sun ;  or,  in  common  language,  Yenus 
will  set  after,  and  Mars  rise  before  the  sun.  All  these 
bodies  at  near  and  far  distances  seem  set  in  the  starry 
dome,  as  the  different  stars  seem  in  Fig.  42,  p.  110. 

The  mysterious  movements  of  advance  and  retreat 
are  rendered  intelligible  by  Fig.  46.  The  planet  Mer- 
cury is  at  A,  and,  seen  from  the  earth,  B  is  located  at  #, 


THE  PLANETS,  AS  SEEN  FROM  SPACE.          113 

on  the  background  of  the  stars  it  seems  to  be  among. 
It  remains  apparently  stationary  at  a  for  some  time,  be- 


Pig.  46. — Apparent  Movements  of  an  Inferior  Planet. 

cause  approaching  the  earth  in  nearly  a  straight  line. 
Passing  D  to  C,  it  appears  to  retrograde  among  the 
stars  to  c  ;  remains  apparently  stationary  for  some  time, 
then,  in  passing  from  C  to  E  and  A,  appears  to  pass 
back  among  the  stars  to  a.  The  progress  of  the  earth, 
meanwhile,  although  it  greatly  retards  the  apparent  mo- 
tion from  A  to  C,  greatly  hastens  it  from  C  to  A. 

It  is  also  apparent  that  Mercury  and  Yenus,  seen 
from  the  earth,  can  never  appear  far  from  the  sun. 
They  must  be  just  behind  the  sun  as  evening  stars,  or 
just  before  it  as  heralds  of  the  morning.  Venus  is  nev- 
er more  than  47°  from  the  sun,  and  Mercury  never  more 
than  30° ;  indeed,  it  keeps  so  near  the  sun  that  very 
few  people  have  ever  seen  the  brilliant  sparkler.  Ob- 
serve how  much  larger  the  planet  appears  near  the  earth 
in  conjunction  at  D  than  in  opposition  at  E.  Observe 
also  what  phases  it  must  present,  and  how  transits  some- 
times take  place. 


1U 


A   SOLAR  SYSTEM. 


The  movement  of  a  superior  planet,  one  whose  orbit 
is  exterior  to  the  earth,  is  clear  from  Fig.  47.  When 
the  earth  is  at  A  and  Mars  at  B,  it  will  appear  among 
the  stars  at  C.  When  the  earth  is  at  D,  Mars  having 
moved  more  slowly  to  E,  will  have  retrograded  to  F.  It 
remains  there  while  the  earth  passes  on,  in  a  line  near- 
ly straight,  from  Mars  to  G ;  then,  as  the  earth  begins 
to  curve  around  the  sun,  Mars  will  appear  to  retraverse 


Fig.  47. — Illustrating  Movements  of  a  Superior  Planet. 

the  distance  from  F  to  C,  and  beyond.  The  farther 
the  superior  planet  is  from  the  earth  the  less  will  be 
the  retrograde  movement. 

The  reader  should  draw  the  orbits  in  proportion,  and, 
remembering  the  relative  speed  of  each  planet,  note  the 
movement  of  each  in  different  parts  of  their  orbits. 

To  account  for  these  most  simple  movements,  the 
earlier  astronomers  invented  the  most  complex  and  im- 
possible machinery.  They  thought  the  earth  the  centre, 
and  that  the  sun,  moon,  and  stars  were  carried  about  it, 
as  stoves  around  a  person  to  warm  him.  They  thought 
these  strange  movements  of  the  planets  were  accom- 
plished by  mounting  them  on  subsidiary  eccentric 
wheels  in  the  revolving  crystal  sphere.  All  that  was 


THE  PLANETS,  AS  SEEN  FROM  SPACE.          115 

needed  to  give  them  a  right  conception  was  a  sinking 
of  their  world  and  themselves  to  an  appropriate  propor- 
tion, and  an  enlargement  of  their  vision,  to  take  in  from 
an  exalted  stand-point  a  view  of  the  simplicity  of  the 
perfect  plan. 

EXPERIMENTS. 

Fix  a  rod,  or  tube,  or  telescope  pointing  at  a  star  in  the  east  or  west, 
and  the  earth's  revolution  will  be  apparent  in  a  moment,  turning  the  tube 
away  from  the  star.  Point  it  at  stars  about  the  north  pole,  and  those 
on  one  side  will  be  found  going  in  an  opposite  direction  from  those  on 
the  other,  and  very  much  slower  than  those  about  the  equator.  Any  one 
can  try  the  pendulum  experiment  who  has  access  to  some  lofty  place 
from  which  to  suspend  the  ball.  It  was  tried  in  Bunker  Hill  Monument 
a  few  years  ago,  and  is  to  be  tried  in  Paris,  in  the  summer  of  1879,  with  a 
seven -hundred -pound  pendulum  and  a  suspending  wire  seventy  yards 
long.  The  advance  and  retrograde  movements  of  planets  can  be  illus- 
trated by  twc  persons  walking  around  a  centre  and  noticing  the  place 
where  the  person  appears  projected  on  the  wall  beyond. 


PROCESSION   OF   STARS  AND  SOULS. 

I  STOOD  upon  the  open  casement, 
And  looked  upon  the  night, 

And  saw  the  westward-going  stars 
Pass  slowly  out  of  sight. 

Slowly  the  bright  procession 
Went  down  the  gleaming  arch, 

And  my  soul  discerned  the  music 
Of  the  long  triumphal  march  ; 

Till  the  great  celestial  army, 
Stretching  far  beyond  the  poles, 

Became  the  eternal  symbol 
Of  the  mighty  march  of  souls. 


116  A  SOLAR  SYSTEM. 

Onward,  forever  onward, 

Red  Mars  led  on  his  clan  ; 
And  the  moon,  like  a  mailed  maiden, 

Was  riding  in  the  van. 

And  some  were  bright  in  beauty, 

And  some  were  faint  and  small, 
But  these  might  be,  in  their  great  heights, 

The  noblest  of  them  all. 

Downward,  forever  downward, 

Behind  earth's  dusky  shore, 
They  passed  into  the  unknown  night — 

They  passed,  and  were  no  more. 

No  more !  oh,  say  not  so ! 

And  downward  is  not  just ; 
For  the  sight  is  weak  and  the  sense  is  dim 

That  looks  through  heated  dust. 

The  stars  and  the  mailed  moon, 
Though  they  seem  to  fall  and  die, 

Still  sweep  in  their  embattled  lines 
An  endless  reach  of  sky. 

And  though  the  hills  of  Death 

May  hide  the  bright  array, 
The  marshalled  brotherhood  of  souls 

Still  keeps  its  onward  way. 

Upward,  forever  upward, 

I  see  their  march  sublime, 
And  hear  the  glorious  music 

Of  the  conquerors  of  Time. 

And  long  let  me  remember 

That  the  palest  fainting  one 
May  to  diviner  vision  be 

A  bright  and  blazing  sun. 

THOMAS  BUCHANAN  READ. 


VII. 

SHOOTING-STARS,  METEORS,  AND 
COMETS. 

"  The  Lord  cast  down  great  stones  from  heaven  upon  them  unto  Aze- 
kah,  and  they  tied."— Joshua  x.  II. 


A    SWAKM    OF    MKTKOUS    MKKTINO    TUB    EAUTII. 


Their  orbits  are  all  parallel.  Those  coming  in  direct  line  to  the  eye  appear  as 
stars,  having  no  motion.  Those  at  one  side  of  this  line  are  seen  in  foreshortened 
perspective.  Those  farthest  from  the  centre,  other  things  being  equal,  appear 
longest.  The  centre,  called  the  radiant  point,  of  these  November  meteors  is  sit- 
uated in  Leo ;  that  of  the  August  meteors  in  Perseus.  Over  fifty  such  radiant 
points  have  been  discovered.  Over  30,000  meteors  have  been  visible  in  au  hour. 


SHOOTING-STARS,  METEORS,  AND  COMETS.       119 


YIL 
SHOOTING-STARS,  METEORS,  AND  COMETS. 

BEFORE  particularly  considering  the  larger  aggrega- 
tions of  matter  called  planets  or  worlds  as  individuals, 
it  is  best  to  investigate  a  part  of  the  solar  system  con- 
sisting of  smaller  collections  of  matter  scattered  every- 
where through  space.  They  are  of  various  densities, 
from  a  cloudlet  of  rarest  gas  to  solid  rock ;  of  various 
sizes,  from  a  grain's  weight  to  little  worlds;  of  vari- 
ous relations  to  each  other,  from  independent  individ- 
uality to  related  streams  millions  of  miles  long.  When 
they  become  visible  they  are  called  shooting-stars,  which 
are  evanescent  star-points  darting  through  the  upper 
air,  leaving  for  an  instant  a  brilliant  train ;  meteors, 
sudden  lights,  having  a  discernible  diameter,  passing 
over  a  large  extent  of  country,  often  exploding  with 
violence  (Fig.  48),  and  throwing  down  upon  the  earth 
aerolites ;  and  comets,  vast  extents  of  ghostly  light, 
that  come  we  know  not  whence  and  go  we  know  not 
whither.  All  these  forms  of  matter  are  governed  by 
the  same  laws  as  the  worlds,  and  are  an  integral  part 
of  the  solar  system — a  part  of  the  unity  of  the  universe. 

Every  one  has  seen  the  so-called  shooting  -  stars. 
They  break  out  with  a  sudden  brilliancy,  shoot  a  few 
degrees  with  quiet  speed,  and  are  gone  before  we  can 
say,  "  See  there  !"  The  cause  of  their  appearance,  the 


120  A  SOLAR  SYSTEM. 

conversion  of  force  into  heat  by  their  contact  with  our 
atmosphere,  has  been  already  explained.  Other  facts 
remain  to  be  studied.  They  are  found  to  appear  about 
seventy  -  three  miles  above  the  earth,  and  to  disappear 


Fig.  48.— Explosion  of  a  Boiide. 

about  twenty  miles  nearer  the  surface.  Their  average 
velocity,  thirty -five,  sometimes  rises  to  one  hundred 
miles  a  second.  They  exhibit  different  colors,  accord- 
ing to  their  different  chemical  substances,  which  are 
consumed.  The  number  of  them  to  be  seen  on  differ- 
ent nights  is  exceedingly  variable ;  sometimes  not  more 


SHOOTING-STARS,  METEORS,  AND   COMETS.        121 

than  five  or  six  an  hour,  and  sometimes  so  many  that 
a  man  cannot  count  those  appearing  in  a  small  section 
of  sky.  This  variability  is  found  to  be  periodic.  There 
are  everywhere  in  space  little  meteoric  masses  of  mat- 
ter, from  the  weight  of  a  grain  to  a  ton,  and  from  the 
density  of  gas  to  rock.  The  earth  meets  7,500,000 
little  bodies  every  day  —  there  is  collision — the  little 
meteoroid  gives  out  its  lightning  sign  of  extinction,  and, 
consumed  in  fervent  heat,  drops  to  the  earth  as  gas  or 
dust.  If  we  add  the  number  light  enough  to  be  seen 
by  a  telescope,  they  cannot  be  less  than  400,000,000  a 
day.  Everywhere  we  go,  in  a  space  as  large  as  that 
occupied  by  the  earth  and  its  atmosphere,  there  must 
be  at  least  13,000  bodies— one  in  20,000,000  cubic  miles 
—  large  enough  to  make  a  light  visible  to  the  naked 
eye,  and  forty  times  that  number  capable  of  revealing 
themselves  to  telescopic  vision.  Professor  Peirce  is 


about  to  publish,  as  the  startling  result  of  his  investi- 
gations, "  that  the  heat  which  the  earth  receives  direct- 
ly from  meteors  is  the  same  in  amount  which  it  re- 
ceives from  the  sun  by  radiation,  and  that  the  sun  re- 
ceives five-sixths  of  its  heat  from  the  meteors  that  fall 
upon  it." 


122 


A   SOLAR  SYSTEM. 


In  1T83  Dr.  Schmidt  was  fortunate  enough  to  have 
a  telescopic  view  of  a  system  of  bodies  which  had  turn- 
ed into  meteors.  These  were  two  larger  bodies  fol- 
lowed by  several  smaller  ones,  going  in  parallel  lines 
till  they  were  extinguished.  They  probably  had  been 
revolving  about  each  other  as  worlds  and  satellites  be- 


Fig.  50.— Saiita  Rosa  Aerolite. 

fore  entering  our  atmosphere.  It  is  more  than  prob- 
able that  the  earth  has  many  such  bodies,  too  small  to 
be  visible,  revolving  around  it  as  moons. 

Aerolites. 

Sometimes  the  bodies  are  large  enough  to  bear  the 
heat,  and  the  unconsurned  centre  comes  to  the  earth. 


SHOOTING-STARS,  METEORS,  AND   COMETS.       123 

Their  velocity  has  been  lessened  by  the  resisting  air, 
and  the  excessive  heat  diminished.  Still,  if  found  soon 
after  their  descent,  they  are  too  hot  to  be  handled. 
These  are  called  aerolites  or  air-stones.  There  was  a 
fall  in  Iowa,  in  February,  1875,  from  which  fragments 
amounting  to  five  hundred  pounds  weight  were  se- 
cured. On  the  evening  of  December  21st,  1876,  a  me- 
teor of  unusual  size  and  brilliancy  passed  over  the 
states  of  Kansas,  Missouri,  Illinois,  Indiana,  and  Ohio. 
It  was  first  seen  in  the  western  part  of  Kansas,  at  an 
altitude  of  about  sixty  miles.  In  crossing  the  State  of 
Missouri  it  began  to  explode,  and  this  breaking  up  con- 
tinued while  passing  Illinois,  Indiana,  and  Ohio,  till  it 
consisted  of  a  large  flock  of  brilliant  balls  chasing  each 
other  across  the  sky,  the  number  being  variously  esti- 
mated at  from  twenty  to  one  hundred.  It  was  accom- 
panied by  terrific  explosions,  and  was  seen  along  a  path 
of  not  less  than  a  thousand  miles.  "When  first  seen  in 
Kansas,  it  is  said  to  have  appeared  as  large  as  the  full 
moon,  and  with  a  train  from  twenty-five  to  one  hun- 
dred feet  long.  Another,  very  similar  in  appearance 
and  behavior,  passed  over  a  part  of  the  same  course  in 
February,  1879.  At  Laigle,  France,  on  April  26th,  1803, 
about  one  o'clock  in  the  day,  from  two  to  three  thou- 
sand fell.  The  largest  did  not  exceed  seventeen  pounds 
weight.  One  fell  in  Weston,  Connecticut,  in  1807, 
weighing  two  hundred  pounds.  A  very  destructive 
shower  is  mentioned  in  the  book  of  Joshua,  chap.  x. 
ver.  11. 

These  bodies  are  not  evenly  distributed  through  space. 
In  some  places  they  are  gathered  into  systems  which 
circle  round  the  sun  in  orbits  as  certain  as  those  of  the 


124:  A   SOLAR  SYSTEM. 

planets.  The  chain  of  asteroids  is  an  illustration  of 
meteoric  bodies  on  a  large  scale.  They  are  hundreds 
in  number  —  meteors  are  millions.  They  have  their 
region  of  travel,  and  the  sun  holds  them  and  the  giant 
Jupiter  by  the  same  power.  The  Power  that  cares  for 
a  world  cares  for  a  sparrow.  If  their  orbit  so  lies  that 
a  planet  passes  through  it,  and  the  planet  and  the  me- 
teors are  at  the  point  of  intersection  at  the  same  time, 
there  must  be  collisions,  and  the  lightning  signs  of  ex- 
tinction proportioned  to  the  number  of  little  bodies  in 
a  given  space. 

It. is  demonstrated  that  the  earth  encounters  more 
than  one  hundred  such  systems  of  meteoric  bodies  in  a 
single  year.  It  passes  through  one  on  the  10th  of  Au- 
gust, another  on  the  llth  of  November.  In  a  certain 
part  of  the  first  there  is  an  agglomeration  of  bodies  suf- 
ficient to  become  visible  as  it  approaches  the  sun,  and 
this  is  known  as  the  comet  of  1862 ;  in  the  second  is  a 
similar  agglomeration,  known  as  Temple's  comet.  It  is 
repeating  the  same  thing  to  say  that  meteoroids  follow  in 
the  train  of  the  comets.  The  probable  orbit  of  the  No- 
vember meteors  and  the  comet  of  1866  is  an  exceeding- 
ly elongated  ellipse,  embracing  the  orbit  of  the  earth  at 
one  end  and  a  portion  of  the  orbit  of  Uranus  at  the 
other  (Fig.  51).  That  of  the  August  meteors  and  the 
comet  of  1862  embraces  the  orbit  of  the  earth  at  one 
end,  and  thirty  per  cent,  of  the  other  end  is  beyond  the 
orbit  of  Neptune. 

In  January,  1846,  Biela's  comet  was  observed  to  be 
divided.  At  its  next  return,  in  1852,  the  parts  were 
1,500,000  miles  apart.  They  could  not  be  found  on 
their  periodic  returns  in  1859, 1865,  and  1872 ;  but  it 


SHOOTING-STARS,  METEORS,  AND   COMETS.      125 


should  have  crossed  the  earth's  orbit  early  in  Septem- 
ber, 1872.  The  earth  itself  would  arrive  at  the  point  of 
crossing  two  or  three  months  later.  If  the  law  of  revo- 
lution held,  we  might  still  expect  to  find  some  of  the 
trailing  meteoroids  of  the  comet  not  gone  by  on  our  ar- 


ofiJLLL 


VHAW/.S 


Fig.  51.— Orbit  of  the  November  Meteors  aud  the  Comet  of  1866. 

rival.  It  was  shown  that  the  point  of  the  earth  that 
would  strike  them  would  be  toward  a  certain  place  in 
the  constellation  of  Andromeda,  if  the  remains  of  the  di- 
luted comet  were  still  there.  The  prediction  was  veri- 
fied in  every  respect.  At  the  appointed  time,  place, 


126  A   SOLAR  SYSTEM. 

and  direction,  the  streaming  lights  were  in  our  sky. 
That  these  little  bodies  belonged  to  the  original  comet 
none  can  doubt.  By  the  perturbations  of  planetary  at- 
traction, or  by  different  original  velocities,  a  comet  may 
be  lengthened  into  an  invisible  stream,  or  an  invisible 
stream  agglomerated  till  it  is  visible  as  a  comet. 

Comets. 

Comets  will  be  most  easily  understood  by  the  fore- 
going considerations.  They  are  often  treated  as  if 
they  were  no  part  of  the  solar  system  ;  but  they  are 
under  the  control  of  the  same  laws,  and  owe  their  ex- 
istence, motion,  and  continuance  to  the  same  causes  as 
Jupiter  arid  the  rest  of  the  planets.  They  are  really 
planets  of  wider  wandering,  greater  ellipticity,  and  less 
density.  They  have  periodic  times  less  than  asteroids, 
and  fifty  times  as  great  as  Neptune.  They  are  little 
clouds  of  gas  or  meteoric  matter,  or  both,  darting  into 
the  solar  system  from  every  side,  at  every  angle  with 
the  plane  of  the  ecliptic,  becoming  luminous  with  re- 
flected light,  passing  the  sun,  and  returning  again  to 
outer  darkness.  Sometimes  they  have  no  tail,  having  a 
nucleus  surrounded  by  nebulosity  like  a  dim  sun  with 
zodiacal  light;  sometimes  one  tail,  sometimes  half  a 
dozen.  These  follow  the  comet  to  perihelion,  and  pre- 
cede it  afterward  (Fig.  52).-  The  orbits  of  some  comets 
are  enormously  elongated ;  one  end  may  lie  inside  the 
earth's  orbit,  and  the  other  end  be  as  far  beyond  Nep- 
tune as  that  is  from  the  sun.  Of  course  only  a  small 
part  of  such  a  curve  can  be  studied  by  us :  the  comet  is 
visible  only  when  near  the  sun.  The  same  curve  around 
the  sun  may  be  an  orbit  that  will  bring  it  back  again,, 


SHOOTING-STARS,  METEORS,  AND    COMETS.       127 


Fig.  52. — Aspects  of  Remarkable  Comets. 

or  one  that  will  carry  it  off  into  infinite  space,  never  to 
return.  One  rate  of  speed  on  that  curve  indicates  an 
elliptical  orbit;  it  returns;  a  greater  rate  of  speed  in- 
dicates that  it  will  take  a  parabolic  orbit,  and  never 
return.  The  exact  rate  of  speed  is  exceedingly  difficult 
to  determine;  hence  it  cannot  be  confidently  asserted 
that  any  comet  ever  visible  will  not  return.  They  may 
all  belong  to  the  solar  system ;  but  some  will  certainly 
be  gone  thousands  of  years  before  their  fiery  forms  will 
greet  the  watchful  eyes  of  dwellers  on  the  earth.  A 
comet  that  has  an  elliptic  orbit  may  have  it  changed  to 


128  A   SOLAR  SYSTEM. 

parabolic  by  the  accelerations  of  its  speed,  by  attracting 
planets;  or  a  parabolic  comet  may  become  elliptic,  and 
so  permanently  attracted  to  the  system  by  the  retarda- 
tions of  attracting  bodies.  A  comet  of  long  period  may  be 
changed  to  one  of  short  period  by  such  attraction,  or  vice 
versa.  Orbits  may  be  changed  without  affecting  speed. 
The  number  of  comets,  like  that  of  meteor  streams, 
is  exceedingly  large.  Five  hundred  have  been  visible 
to  the  naked  eye  since  the  Christian  era.  Two  hun- 
dred have  been  seen  by  telescopes  invented  since  their 
invention.  Some  authorities  estimate  the  number  be- 
longing to  our  solar  system  by  millions ;  Professor 
Peirce  says  more  than  five  thousand  millions. 

Famous  Comets. 

The  comet  of  1680  is  perhaps  the  one  that  appeared 
in  A.D.  44,  soon  after  the  death  of  Julius  Caesar,  also  in 
the  reign  of  Justinian,  A.D.  531,  and  in  1106.  This  is 
not  determined  by  any  recognizable  resemblance.  It 
had  a  tail  70°  long;  it  was  not  all  arisen  when  its  head 
reached  the  meridian.  It  is  possible,  from  the  shape  of 
its  orbit,  that  it  has  a  periodic  time  of  nine  thousand 
years,  or  that  it  may  have  a  parabolic  orbit,  and  never 
return.  Observations  taken  two  hundred  years  ago  have 
not  the  exactness  necessary  to  determine  so  delicate  a 
point. 

On  August  19th,  1682,  Halley  discovered  a  comet 
which  he  soon  declared  to  be  one  seen  by  Kepler  in 
1607.  Looking  back  still  farther,  he  found  that  a  com- 
et was  seen  in  1531  having  the  same  orbit.  Still  far- 
ther, by  the  same  exact  period  of  seventy-five  years,  he 
found  that  it  was  the  same  comet  that  had  disturbed 


SHOOTING-STARS,  METEORS,  AND   COMETS.      129 

the  equanimity  of  Pope  Calixtus  in  1456.  Calculations 
were  undertaken  as  to  the  result  of  all  the  accelerations 
and  retardations  by  the  attractions  of  all  the  planets  for 
the  next  seventy-five  years.  There  was  not  time  to  fin- 
ish all  the  work ;  but  a  retardation  of  six  hundred  and 
eighteen  days  was  determined,  with  a  possible  error  of 
thirty  days.  The  comet  actually  came  to  time  within 
thirty-three  days,  on  March  12th,  1759.  Again  its  re- 
turn was  calculated  with  more  laborious  care.  It  came 
to  time  and  passed  the  sun  within  three  days  of  the  pre- 
dicted time,  on  the  16th  of  November,  1835.  It  passed 
from  sight  of  the  most  powerful  telescopes  the  follow- 
ing May,  and  has  never  since  been  seen  by  human  eye. 
But  the  eye  of  science  sees  it  as  having  passed  its 
aphelion  beyond  the  orbit  of  Neptune  in  1873,  and  is 
already  hastening  back  to  the  warmth  and  light  of  the 
sun.  It  will  be  looked  for  in  1911 ;  and  there  is  good 
hope  of  predicting,  long  before  it  is  seen,  the  time  of 
its  perihelion  within  a  day. 

Bieltfs  lost  Comet. — This  was  a  comet  with  a  periodic 
time  of  six  years  and  eight  months.  It  was  observed 
in  January,  1846,  to  have  separated  into  two  parts  of 
unequal  brightness.  The  lesser  part  grew  for  a  month 
until  it  equalled  the  other,  then  became  smaller  and 
disappeared,  while  the  other  was  visible  a  month  longer. 
At  disappearance  the  parts  were  200,000  miles  asunder. 
On  its  next  return,  in  1852,  the  parts  were  1,500,000 
miles  apart ;  sometimes  one  was  brighter  and  sometimes 
the  other ;  which  was  the  fragment  and  which  was  the 
main  body  could  not  be  recognized.  They  vanished  in 
September,  1852,  and  have  never  been  seen  since.  Three 
revolutions  have  been  made  since  that  time,  but  no 

6* 


130  A   SOLAR  SYSTEM. 

trace  of  it  could  be  discovered.  Probably  the  same  in- 
fluence that  separated  it  into  parts,  separated  the  par- 
ticles till  too  thin  and  tenuous  to  be  seen.  There  is 
ground  for  believing  that  the  earth  passed  through  a 
part  of  it,  as  before  stated  under  the  head  of  meteors. 

The  Great  Comet  of  184:3  passed  nearer  the  sun  than 
any  known  body.  It  almost  grazed  the  sun.  If  it  ever 
returns,  it  will  be  in  A.D.  2373. 

Donates  Comet  of  1858. — This  was  one  of  the  most 
magnificent  of  modern  times.  During  the  first  three 
months  it  showed  no  tail,  but  from  August  to  October 
it  had  developed  one  forty  degrees  in  length.  Its  period 
is  about  two  thousand  years.  Every  reader  remembers 
the  comet  of  the  summer  of  1874. 

Enckds  Comet. — This  comet  has  become  famous  for 
its  supposed  confirmation  of  the  theory  that  space  was 
filled  with  a  substance  infinitely  tenuous,  which  resisted 
the  passage  of  this  gaseous  body  in  an  appreciable  de- 
gree, and  in  long  ages  would  so  retard  the  motion  of  all 
the  planets  that  gravitation  would  draw  them  all  one 
by  one  into  the  sun.  We  must  not  be  misled  by  the 
term  retardation  to  suppose  it  means  behind  time,  for  a 
retarded  body  is  before  time.  If  its  velocity  is  dimin- 
ished, the  attraction  of  the  sun  causes  it  to  take  a  small- 
er orbit,  and  smaller  orbits  mean  increased  speed — hence 
the  supposed  retardation  would  shorten  its  periodic 
time.  This  comet  was  thought  to  be  retarded  two  and 
a  half  hours  at  each  revolution.  If  it  was,  it  would  not 
prove  the  existence  of  the  resisting  medium.  Other 
causes,  unknown  to  us,  might  account  for  it.  Subse- 
quent and  more  exact  calculations  fail  to  find  any  re- 
tardations in  at  least  two  revolutions  between  1865  and 


SHOOTING-STARS,  METEORS,  AND   COMETS.       131 

1871.  Indications  point  to  a  retardation  of  one  and  a 
half  hours  both  before  and  since.  But  such  discrep- 
ancy of  result  proves  nothing  concerning  a  resisting 
medium,  but  rather  is  an  argument  against  its  existence. 
Besides,  Faye's  comet,  in  four  revolutions  of  seven  years 
each,  shows  no  sign  of  retardation. 

The  truth  may  be  this,  that  a  kind  of  atmosphere  ex- 
ists around  the  sun,  perhaps  revealed  by  the  zodiacal 
light,  that  reaches  beyond  where  Encke's  comet  dips  in- 
side the  orbit  of  Mercury,  and  thus  retards  this  body, 
but  does  not  reach  beyond  the  orbit  of  Mars,  where 
Faye's  comet  wheels  and  withdraws. 

Of  what  do  Comets  consist? 

The  unsolved  problems  pertaining  to  comets  are  very 
numerous  and  exceedingly  delicate.  Whence  come 
they  ?  Why  did  they  not  contract  to  centres  of  nebu- 
lae? Are  there  regions  where  attractions  are  balanced, 
and  matter  is  left  to  contract  on  itself,  till  the  move- 
ments of  suns  and  planets  adds  or  diminishes  attrac- 
tive force  on  one  side,  and  so  allows  them  to  be  drawn 
slowly  toward  one  planet,  and  its  sun,  or  another? 
There  is  ground  for  thinking  that  the  comet  of  1866 
and  its  train  of  meteors,  visible  to  us  in  November,  was 
thus  drawn  into  our  system  by  the  planet  Uranus.  In- 
deed, Leverrier  has  conjecturally  fixed  upon  the  date 
of  A.D.  128  as  the  time  when  it  occurred;  but  another 
and  closer  observation  of  its  next  return,  in  1899,  will 
be  needed  to  give  confirmation  to  the  opinion.  Our 
sun's  authority  extends  at  least  half-way  to  the  nearest 
fixed  star,  one  hundred  thousand  times  farther  than  the 
orbit  of  the  earth.  Meteoric  and  cometary  matter  ly- 


132  A   SOLAR  SYSTEM. 

ing  there,  in  a  spherical  shell  about  the  solar  system, 
balanced  between  the  attraction  of  different  suns,  final- 
ly feels  the  power  that  determines  its  destiny  toward 
our  sun.  It  would  take  167,000,000  years  to  come 
thence  to  our  system. 

The  conditions  of  matter  with  which  we  are  acquaint- 
ed do  not  cover  all  the  ground  presented  by  these  mys- 
terious visitors.  We  know  a  gas  sixteen  times  as  light 
as  air,  but  hydrogen  is  vastly  too  heavy  and  dense ;  for 
we  see  the  faintest  star  through  thousands  of  miles  of 
cometary  matter;  we  know  that  water  may  become 
cloudy  vapor,  but  a  little  of  it  obscures  the  vision. 
Into  what  more  ethereal,  and  we  might  almost  say  spir- 
itual, forms  matter  may  be  changed  we  cannot  tell.  But 
if  wre  conceive  comets  to  be  only  gas,  it  would  expand 
indefinitely  in  the  realms  of  space,  where  there  is  no 
force  of  compression  but  its  own.  We  might  say  that 
comets  are  composed  of  small  separate  masses  of  mat- 
ter, hundreds  of  miles  apart;  and, looking  through  thou- 
sands of  miles  of  them,  we  see  light  enough  reflected 
from  them  all  to  seem  continuous.  Doubtless  that  is 
sometimes  the  case.  But  the  spectroscope  shows  anoth- 
er state  of  things:  it  reveals  in  some  of  these  comets 
an  incandescent  gas — usually  some  of  the  combinations 
of  carbon.  The  conclusion,  then,  naturally  is  that  there 
are  both  gas  and  small  masses  of  matter,  each  with  an 
orbit  of  its  own  nearly  parallel  to  those  of  all  the  others, 
and  that  they  afford  some  attraction  to  hold  the  mass 
of  intermingled  and  confluent  gas  together.  Our  best 
judgment,  then,  is  that  the  nucleus  is  composed  of  sepa- 
rate bodies,  or  matter  in  a  liquid  condition,  capable  of 
being  vaporized  by  the  heat  of  the  sun,  and  driven  off, 


SHOOTING-STARS,  METEORS,  AND   COMETS.       133 

as  steam  from  a  locomotive,  into  a  tail.  Indications  of 
this  are  found  in  the  fact  that  tails  grow  smaller  at  suc- 
cessive returns,  as  the  matter  capable  of  such  vaporiza- 
tion becomes  condensed.  In  some  instances,  as  in  that 
of  the  comet  of  1843,  the  head  was  diminished  by  the 
manufacture  of  a  tail.  On  the  other  hand,  Professor 
Peirce  showed  that  the  nucleus  of  the  comets  of  1680, 
1843,  and  1858  must  have  had  a  tenacity  equal  to  steel, 
to  prevent  being  pulled  apart  by  the  tidal  forces  caused 
by  its  terrible  perihelion  sweep  around  the  sun. 

It  is  likely  that  there  are  great  varieties  of  condition 
in  different  comets,  and  in  the  same  comet  at  times. 
We  see  them  but  a  few  days  out  of  the  possible  millions 
of  their  periodic  time ;  we  see  them  only  close  to  the 
sun,  under  the  spur  of  its  tremendous  attraction  and 
terrible  heat.  This  gives  us  ample  knowledge  of  the 
path  of  their  orbit  and  time  of  their  revolution,  but 
little  ground  for  judgment  of  their  condition,  when  they 
slowly  round  the  uttermost  cape  of  their  far-voyaging, 
in  the  terrible  cold  and  darkness,  to  commence  their 
homeward  flight.  The  unsolved  problems  are  not  all 
in  the  distant  sun  and  more  distant  stars,  but  one  of 
them  is  carried  by  us,  sometimes  near,  sometimes  far 
off ;  but  our  acquaintance  with  the  possible  forms  and 
conditions  of  matter  is  too  limited  to  enable  us  to  mas- 
ter the  difficulties. 

WiU  Comets  strike  the  Earth  ? 

Very  likely,  since  one  or  two  have  done  so  within  a 
recent  period.  What  will  be  the  effect  ?  That  depends 
on  circumstances.  There  is  good  reason  to  suppose  we 
passed  through  the  tail  of  a  comet  in  1861,  and  the  only 


134  A   SOLAR  SYSTEM. 

observable  effect  was  a  peculiar  phosphorescent  mist. 
If  the  comet  were  composed  of  small  meteoric  masses  a 
brilliant  shower  would  be  the  result.  But  if  we  fairly 
encountered  a  nucleus  of  any  considerable  mass  and  so- 
lidity, the  result  would  be  far  more  serious.  The  mass 
of  Donati's  comet  has  been  estimated  by  M.  Faye  to 
be  inrumr  of  that  of  the  earth.  If  this  amount  of  matter 
were  dense  as  water,  it  would  make  a  globe  five  hun- 
dred miles  in  diameter;  and  if  as  dense  as  Professor 
Peirce  proved  the  nucleus  of  this  comet  to  be,  its  im- 
pact with  the  earth  would  develop  heat  enough  to  melt 
and  vaporize  the  hardest  rocks.  Happily  there  is  little 
fear  of  this:  as  Professor  Newcomb  says,  "So  small  is 
the  earth  in  comparison  with  celestial  space,  that  if  one 
were  to  shut  his  eyes  and  fire  at  random  in  the  air,  the 
chance  of  bringing  down  a  bird  would  be  better  than 
that  of  a  comet  of  any  kind  striking  the  earth."  Be- 
sides, we  are  not  living  under  a  government  of  chance, 
but  under  that  of  an  Almighty  Father,  who  upholdeth 
all  things  by  the  word  of  his  power;  and  no  world  can 
come  to  ruin  till  he  sees  that  it  is  best. 


THE   PLANETS   AS   INDIVIDUALS. 

"Through  faith  we  understand  that  the  worlds  [plum I J  were  framed 
by  the  word  of  God,  so  that  things  which  are  seen  were  not  made  of 
tilings  which  do  appear." — Heb.  xi.  3. 


"  O  rich  and  various  man  !  thou  palace  of  sight  and  sound,  carrying  in 
thy  senses  the  morning,  and  the  night,  and  the  unfathomable  galaxy ;  in 
thy  brain  the  geometry  of  the  city  of  God  ;  in  thy  heart  the  power  of  love, 
and  the  realms  of  right  and  wrong.  An  individual  man  is  a  fruit  which 
it  costs  all  the  foregoing  ages  to  form  and  ripen.  He  is  strong,  not  to  do 
but  to  live ;  not  in  his  arms,  but  in  his  heart ;  not  as  an  agent,  but  as  a 
fact." — EMERSON. 


THE  PLANETS  AS  INDIVIDUALS.  137 


VIII. 
THE  PLANETS  AS  INDIVIDUALS. 

How  many  bodies  there  may  be  revolving  about  the 
sun  we  have  no  means  to  determine  or  arithmetic  to 
express.  When  the  new  star  of  the  American  Repub- 
lic appeared,  there  were  but  six  planets  discovered. 
Since  then  three  regions  of  the  solar  system  have  been 
explored  with  wonderful  success.  The  outlying  realms 
beyond  Saturn  yielded  the  planet  Uranus  in  1781,  and 
Neptune  in  1846.  The  middle  region  between  Jupiter 
and  Mars  yielded  the  little  planetoid  Ceres  in  1801, 
Pallas  in  1802,  and  one  hundred  and  ninety  others 
since.  The  inner  region  between  Mercury  and  the  sun 
is  of  necessity  full  of  small  meteoric  bodies ;  the  ques- 
tion is,  are  there  any  bodies  large  enough  to  be  seen  ? 

The  same  great  genius  of  Leverrier  that  gave  us  Nep- 
tune from  the  observed  perturbations  of  Uranus,  point- 
ed out  perturbations  in  Mercury  that  necessitated  either 
a  planet  or  a  group  of  planetoids  between  Mercury  and 
the  sun.  Theoretical  astronomers,  aided  by  the  fact 
that  no  planet  had  certainly  been  seen,  and  that  all  as- 
serted discoveries  of  one  had  been  by  inexperienced  ob- 
servers, inclined  to  the  belief  in  a  group,  or  that  the  dis- 
turbance was  caused  by  the  matter  reflecting  the  zodi- 
acal light. 

When  the  total  eclipse  of  the  sun  occurred  in  1878, 


138  A   SOLAR  SYSTEM. 

astronomers  were  determined  that  the  question  of  the 
existence  of  an  intra-mercurial  planet  should  be  settled. 
Maps  of  all  the  stars  in  the  region  of  the  sun  were  care- 
fully studied,  sections  of  the  sky  about  the  sun  were  as- 
signed to  different  observers,  who  should  attend  to  noth- 

O  ' 

ing  but  to  look  for  a  possible  planet.  It  is  now  con- 
ceded that  Professor  Watson  and  Lewis  Swift,  the  fa- 
mous comet-finder,  each  discovered  two  small  bodies — 
four  in  all — within  the  orbit  of  Mercury.  Instead  of 
one  Vulcan  there  are  doubtless  many  planetoids.  One 
was  seen  during  the  eclipse  of  January  llth,  1880. 
They  are  about  13,000,000  miles  from  the  sun,  and 
make  a  revolution  in  about  twenty  days. 

MERCURY. 

The  swift  messenger  of  the  gods ;  sign  $,  his  caducens. 

Distance  from  the  sun,  35,750,000  miles.  Diameter,  2992 
miles.  Orbital  revolution,  87.97  days.  Orbital  velocity,  1773 
miles  per  minute.  Axial  revolution,  24h.  5m. 

Mercury  shines  with  a  white  light  nearly  as  bright  as 
Sirius ;  is  always  near  the  horizon.  When  nearly  be- 
tween us  and  the  sun,  as  at  D  (Fig.  46,  p.  113),  its  illu- 
minated side  nearly  opposite  to  us,  we,  looking  from  E, 
see  only  a  thin  crescent  of  its  light.  When  it  is  at  its 
greatest  angular  distance  from  the  sun,  as  A  or  C,  we 
see  it  illuminated  like  the  half-moon.  When  it  is  be- 
yond the  sun,  as  at  E,  we  see  its  whole  illuminated  face 
like  the  full-moon. 

The  variation  of  its  apparent  size  from  the  varying 
distance  is  very  striking.  At  its  extreme  distance  from 
the  earth  it  subtends  an  angle  of  only  five  seconds  ;  near- 
est to  us,  an  angle  of  twelve  seconds.  Its  distance  from 
the  earth  varies  nearly  as  one  to  three,  and  its  apparent 
size  in  the  inverse  ratio. 


THE  PLANETS  AS  INDIVIDUALS.  139 

When  Mercury  comes  between  the  earth  and  the  sun, 
near  the  line  where  the  planes  of  their  -orbits  cut  each 
other  by  reason  of  their  inclination,  the  dark  body  of 
Mercury  will  be  seen  on  the  bright  surface  of  the  sun. 
This  is  called  a  transit.  If  it  goes  across  the  centre  of 
the  sun  it  may  consume  eight  hours.  It  goes  100,000 
miles  an  hour,  and  has  860,000  miles  of  disk  to  cross. 
The  transit  of  1878  occupied  seven  and  a  half  hours. 
The  transits  for  the  remainder  of  the  century  will 
occur : 


November  Ttl) 1881 

May  9th 1891 


November  10th 1894 

November  4th 1901 


VENUS. 

Goddess  of  beauty;  its  sign  $,  a  mirror. 

Distance  from  the  sun,  66,750,000  miles.  Diameter,  7660 
miles.  Orbital  Velocity,  1296  miles  per  minute.  Axial  rev- 
olution, 23h,  21m.  Orbital  revolution,  224.7  days. 

This  brilliant  planet  is  often  visible  in  the  daytime. 
I  was  once  delighted  by  seeing  Venus  looking  down,  a 
little  after  mid-day,  through  the  open  space  in  the  dome 
of  the  Pantheon  at  Rome.  It  has  never  since  seemed 
to  me  as  if  the  home  of  all  the  gods  was  deserted. 
Phoebus,  Diana,  Yenus  and  the  rest,  thronged  through 
that  open  upper  door  at  noon  of  night  or  day.  Arago 
relates  that  Bonaparte,  upon  repairing  to  Luxemburg 
when  the  Directory  was  about  to  give  him  a  fete,  was 
much  surprised  at  seeing  the  multitude  paying  more 
attention  to  the  heavens  above  the  palace  than  to  him 
or  his  brilliant  staff.  Upon  inquiry,  he  learned  that 
these  curious  persons  were  observing  with  astonishment 
a  star  which  they  supposed  to  be  that  of  the  conqueror 
of  Italy.  The  emperor  himself  was  not  indifferent  when 


140  A   SOLAR  SYSTEM. 

his  piercing  eye  caught  the  clear  lustre  of  Venus  smil- 
ing upon  him  at  rnid-day. 

This  unusual  brightness  occurs  when  Yenus  is  about 
five  weeks  before  or  after  her  inferior  conjunction,  and 
also  nearest  overhead  by  being  north  of  the  sun.  This 
last  circumstance  occurs  once  in  eight  years,  and  came 
on  February  16th,  1878. 

Venus  may  be  as  near  the  earth  as  22,000,000  miles, 
and  as  far  away  as  160,000,000.  This  variation  of  its 
distances  from  the  earth  is  obviously  much  greater  than 
that  of  Mercury,  and  its  consequent  apparent  size  much 
more  changeable.  Its  greatest  and  least  apparent  sizes 
are  as  ten  and  sixty-five  (Fig.  53). 

o  °  o 

O  ^t^fer  ^ 

C  3 

f)  ^^  d 

•     •      * 

Fig.  53 Phases  of  Venns,  and  Various  Apparent  Dimensions. 

When  Copernicus  announced  the  true  theory  of  the 
solar  system,  he  said  that  if  the  inferior  planets  could 
be  clearly  seen  they  would  show  phases  like  the  moon. 
When  Galileo  turned  the  little  telescope  he  had  made 
on  Venus,  he  confirmed  the  prophecy  of  Copernicus. 
Desiring  to  take  time  for  more  extended  observation, 
and  still  be  able  to  assert  the  priority  of  his  discovery, 
he  published  the  following  anagram,  in  which  his  dis- 
covery was  contained : 


THE  EARTH.  141 

"  Haec  immatnra  a  me  jam  frustra  leguntur  o.  y." 
(These  unripe  things  are  now  vainly  gathered  by  me.) 

He  first  saw  Verms  as  gibbous ;  a  few  months  revealed 
it  as  crescent,  and  then  he  transposed  his  anagram  into : 

"  Cynthiae  figuras  aemulatur  mater  amorum." 
(The  mother  of  loves  imitates  the  phases  of  Cynthia.) 

Many  things  that  were  once  supposed  to  be  known 
concerning  Yenus  are  not  confirmed  by  later  and  better 
observations.  Yenus  is  surrounded  by  an  atmosphere  so 
dense  with  clouds  that  it  is  conceded  that  her  time  of 
rotation  and  the  inclination  of  her  axis  cannot  be  deter- 
mined. She  revealed  one  of  the  grandest  secrets  of  the 
universe  to  the  first  seeker ;  showed  her  highest  beauty 
to  her  first  ardent  lover,  and  has  veiled  herself  from  the 
prying  eyes  of  later  comers. 

Florence  has  built  a  kind  of  shrine  for  the  telescope 
of  Galileo.  By  it  he  discovered  the  phases  of  Yenus, 
the  spots  on  the  sun,  the  mountains  of  the  moon,  the 
satellites  of  Jupiter,  and  some  irregularities  of  shape  in 
Saturn,  caused  by  its  rings.  Galileo  subsequently  be- 
came blind,  but  he  had  used  his  eyes  to  the  best  pur- 
pose of  any  man  in  his  generation. 

THE   EARTH. 

Its  sign  ©. 

Distance  from  the  sun,  92,500,000  milea  Diameter,  polar, 
7899  miles ;  equatorial,  7925^  miles.  Axial  revolution,  23h. 
56m.  4.09s.;  orbital,  365.26.  Orbital  velocity  per  minute, 
1102.8  miles. 

Let  us  lift  ourselves  up  a  thousand  miles  from  the 
earth.  We  see  it  as  a  ball  hung  upon  nothing  in  emp- 
ty space.  As  the  drop  of  falling  water  gathers  itself 


142  A   SOLAR  SYSTEM. 

into  a  sphere  by  its  own  inherent  attraction,  so  the 
earth  gathers  itself  into  a  ball.      Noticing  closely,  we 


Fig.  54 — Earth  and  Moon  in  Space. 

see  forms  of  continents  outlined  in  bright  relief,  and 
oceanic  forms  in  darker  surfaces.  We  see  that  its  axis 
of  revolution  is  nearly  perpendicular  to  the  line  of  light 
from  the  sun.  One-half  is  always  dark.  The  sunrise 
greets  a  new  thousand  miles  every  hour ;  the  glories  of 


AURORA  BOREALIS.  143 

the  sunset  follow  over  an  equal  space,  180°  behind.    We 
are  glad  that  the  darkness  never  overtakes  the  morning. 

The  Aurora  Borealis. 

While  east  and  west  are  gorgeous  with  sunrise  and 
sunset,  the  north  is  often  more  glorious  with  its  aurora 
borealis.  We  remember  that  all  worlds  have  weird 


Fig.  55.— The  Anrora  as  Waving  Ctirtains. 

and  inexplicable  appendages.  They  are  not  limited  to 
their  solid  surfaces  or  their  circumambient  air.  The  sun 
has  its  fiery  flames,  corona,  zodiacal  light,  and  perhaps  a 
finer  kind  of  atmosphere  than  we  know.  The  earth  is 


144:  A  SOLAR  SYSTEM. 

not  without  its  inexplicable  surroundings.  It  lias  not 
only  its  gorgeous  eastern  sunrise,  its  glorious  western 
sunset,  high  above  its  surface  in  the  clouds,  but  it  also 
has  its  more  glorious  northern  dawn  far  above  its  clouds 
and  air.  The  realm  of  this  royal  splendor  is  as  yet  an 
unconquered  world  waiting  for  its  Alexander.  There 
are  certain  observable  facts,  viz.,  it  prevails  mostly  near 
the  arctic  circle  rather  than  the  pole ;  it  takes  on  vari- 
ous forms — cloud-like,  arched,  straight;  it  streams  like 
banners,  waves  like  curtains  in  the  wind,  is  inconstant ; 
is  either  the  cause  or  result  of  electric  disturbance ;  it 
is  often  from  four  hundred  to  six  hundred  miles  above 
the  earth,  while  our  air  cannot  be  over  one  hundred 
miles.  It  almost  seems  like  a  revelation  to  human  eyes 
of  those  vast,  changeable,  panoramic  pictures  by  which 
the  inhabitants  of  heaven  are  taught. 

Investigation  has  discovered  far  more  mysteries  than 
it  has  explained.  It  is  possible  that  the  same  cause  that 
produces  sun-spots  produces  aurora  in  all  space,  visible 
in  all  worlds.  If  so,  we  shall  see  more  abundant  auroras 
at  the  next  maximum  of  sun-spot,  between  1880-84. 

The  Delicate  Balance  of  Forces. 

A  soap-bubble  in  the  wind  could  hardly  be  more  flex- 
ible in  form  and  sensitive  to  influence  than  is  the  earth. 
On  the  morning  of  May  9th,  1876,  the  earth's  crust  at 
Peru  gave  a  few  great  throbs  upward,  by  the  action  of 
expansive  gases  within.  The  sea  fled,  and  returned  in 
great  waves  as  the  land  rose  and  fell.  Then  these  waves 
fled  away  over  the  great  mobile  surface,  and  in  less  than 
five  hours  they  had  covered  a  space  equal  to  half  of  Eu- 
rope. The  waves  ran  out  to  the  Sandwich  Islands,  six 


THE  EARTH.  14:5 

thousand  miles,  at  the  rate  of  five  hundred  miles  an 
hour,  and  arrived  there  thirty  feet  high.  They  not  only 
sped  on  in  straight  radial  lines,  but,  having  run  up  the 
coast  to  California,  were  deflected  away  into  the  former 
series  of  waves,  making  the  most  complex  undulations. 
Similar  beats  of  the  great  heart  of  the  earth  have  sent 
its  pulses  as  widely  and  rapidly  on  previous  occasions. 

The  figure  of  the  earth,  even  on  the  ocean,  is  irregu- 
lar, in  consequence  of  the  greater  preponderance  of  land 
—  and  hence  greater  density  —  in  the  northern  hemi- 
sphere. These  irregularities  are  often  very  perplexing 
in  making  exact  geodetic  measurements.  The  tendency 
of  matter  to  fly  from  the  centre  by  reason  of  revolu- 
tion causes  the  equatorial  diameter  to  be  twenty -six 
miles  longer  than  the  polar  one.  By  this  force  the 
Mississippi  River  is  enabled  to  run  up  a  hill  nearly 
three  miles  high  at  a  very  rapid  rato.  Its  mouth  is 
that  distance  farther  from  the  centre  of  the  earth  than 
its  source,  when  but  for  this  rotation  both  points  would 
be  equally  distant. 

If  the  water  became  more  dense,  or  if  the  world  were 
to  revolve  faster,  the  oceans  would  rush  to  the  equator, 
burying  the  tallest  mountains  and  leaving  polar  regions 
bare.  If  the  water  should  become  lighter  in  a  very 
slight  degree,  or  the  world  rotate  more  slowly,  the 
poles  would  be  submerged  and  the  equator  become  an 
arid  waste.  No  balance,  turning  to  y^W  of  a  grain,  is 
more  delicate  than  the  poise  of  forces  on  the  world. 
Laplace  has  given  us  proof  that  the  period  of  the  earth's 
axial  rotation  has  not  changed  -j-J7  of  a  second  of  time 
in  two  thousand  years. 

7 


146  A  SOLAR  SYSTEM. 

Tides. 

But  there  is  an  outside  influence  that  is  constantly 
acting  upon  the  earth,  and  to  which  it  constantly  re- 
sponds. Two  hundred  and  forty  thousand  miles  from 
the  earth  is  the  moon,  having  ¥TT  the  mass  of  the  world. 
Its  attractive  influence  on  the  earth  causes  the  mov- 
able and  nearer  portions  to  hurry  away  from  the  more 
stable  and  distant,  and  heap  themselves  up  on  that  part 
of  the  earth  nearest  the  moon.  Gravitation  is  inverse- 
ly as  the  square  of  the  distance;  hence  the  water  on 
the  surface  of  the  earth  is  attracted  more  than  the  body 
of  the  earth,  some  parts  of  which  are  eight  thousand 
miles  farther  off;  hence  the  water  rises  on  the  side  next 
the  moon.  But  the  earth,  as  a  whole,  is  nearer  the 
moon  than  the  wrater  on  the  opposite  side,  and  being 
drawn  more  strongly,  is  taken  away  from  the  water, 
leaving  it  heaped  up  also  on  the  side  opposite  to  the 
moon. 

A  subsidiary  cause  of  tides  is  found  in  the  revolution 
of  the  earth  and  moon  about  their  common  centre  of 
gravity.  Revolution  about  an  axis  through  the  centre 
of  a  sphere  enlarges  the  equator  by  centrifugal  force. 
Revolution  about  an  axis  touching  the  surface  of  a  flex- 
ible globe  converts  it  into  an  egg-shaped  body,  with 
the  longer  axis  perpendicular  to  the  axis  of  revolution. 
In  Fig.  56  the  point  of  revolution  is  seen  at  the  centre 
of  gravity  at  G ;  hence,  in  the  revolution  of  earth  and 
moon  as  one,  a  strong  centrifugal  force  is  caused  at  D, 
and  a  less  one  at  C.  This  gives  greater  height  to  the 
tides  than  the  attraction  of  the  moon  alone  could  pro- 
duce. 


TIDES.  147 

If  the  earth  had  no  axial  revolution,  the  attractive 
point  where  the  tide  rises  would  be  carried  around  the 


Fig.  56. 

earth  once  in  twenty-seven  days  by  the  moon's  revolu- 
tion about  the  earth.  But  since  the  earth  revolves  on 
its  axis,  it  presents  a  new  section  to  the  moon's  attrac- 
tion every  hour.  If  the  moon  were  stationary,  that 
would  bring  two  high  tides  in  exactly  twenty -four 
hours ;  but  as  the  moon  goes  forward,  we  need  nearly 
twenty-five  hours  for  two  tides. 

The  attractive  influence  of  the  sun  also  gives  us  a 
tide  four-tenths  as  great  as  that  of  the  moon.  When 
these  two  influences  of  the  sun  and  moon  combine,  as 
they  do,  in  conjunction — when  both  bodies  are  on  one 
side  of  the  earth ;  or  in  opposition,  sun  and  moon  being 
on  opposite  sides  of  the  earth — we  have  spring  or  in- 
creased tides.  When  the  moon  closes  its  first  or  third 
quarter,  i.  <?.,  when  a  line  from  the  moon  to  the  earth 
makes  a  right  angle  with  one  from  the  sun  to  the  earth, 
these  influences  antagonize  one  another,  and  we  have 
the  neap  or  low  tides. 

It  is  easy  to  see  that  if,  when  the  moon  was  drawing 
its  usual  tide,  the  sun  drew  four-tenths  of  the  water  in 
a  tide  at  right  angles  with  it,  the  moon's  tide  must  be 
by  so  much  lower.  Because  of  the  inertia  of  the  water 


148  A  SOLAR  SYSTEM. 

it  does  riot  yield  instantly  to  the  moon's  influence,  and 
the  crest  of  the  tide  is  some  hours  behind  the  advan- 
cing moon. 

The  amount  of  tide  in  various  places  is  affected  by 
almost  innumerable  influences,  as  distance  of  moon  at 
its  apogee  or  perigee ;  its  position  north,  south,  or  at  the 
equator ;  distance  of  earth  from  sun  at  perihelion  and 
aphelion ;  the  position  of  islands ;  the  trend  of  conti- 
nents, etc.  All  eastern  shores  have  far  greater  tides  than 
western.  As  the  earth  rolls  to  the  east  it  leaves  the 
tide-crest  under  the  moon  to  impinge  on  eastern  shores, 
hence  the  tides  of  from  seventy-ti ve  to  one  hundred  feet 
in  the  Bay  of  Fundy.  Lakes  and  most  seas  are  too  small 
to  have  perceptible  tides.  The  spring-tides  in  the  Med- 
iterranean Sea  are  only  about  three  inches. 

This  constant  ebb  and  flow  of  the  great  sea  is  a  grand 
provision  for  its  purification.  Even  the  wind  is  sent  to 
the  sea  to  be  cleansed.  The  sea  washes  every  shore, 
purifies  every  cove,  bay,  and  river  twice  every  twenty- 
four  hours.  All  putrescible  matter  liable  to  breed  a 
pestilence  is  carried  far  from  shore  and  sunk  under 
fathoms  of  the  never-stagnant  sea.  The  distant  moon 
lends  its  mighty  power  to  carry  the  burdens  of  com- 
merce. She  takes  all  the  loads  that  can  be  floated  on 
her  flowing  tides,  and  cheerfully  carries  them  in  oppo- 
site directions  in  successive  journeys. 

It  must  be  conceded  that  the  profoundest  study  has 
not  mastered  the  whole  philosophy  of  tides.  There  are 
certain  facts  which  are  apparent,  but  for  an  explanation 
of  their  true  theory  such  man  as  Laplace,  Newton,  and 
Airy  have  labored  in  vain.  There  are  plenty  of  other 
worlds  still  to  conquer. 


Fig.  57. — Lunar  Day. 


THE  MO  OX.  151 

THE  MOOX. 

New  moon,  •  ;  first  quarter,  3  ;  full  moon,  o  ;  last  quarter,  £. 

Extreme  distance  from  the  earth,  259,600  miles;  least. 
221,000  miles;  mean,  240,000  miles.  Diameter,  2164.6  miles 
[2153,  Lockyer].  Revolution  about  the  earth,  29|  days.  Ax- 
ial revolution,  same  time. 

When  the  astronomer  Herschel  was  observing  the 
southern  sky  from  the  Cape  of  Good  Hope,  the  most 
clever  hoax  was  perpetrated  that  ever  was  palmed  upon 
a  credulous  public.  Some  new  and  wonderful  instru- 
ments were  carefully  described  as  having  been  used  by 
that  astronomer,  whereby  he  was  enabled  to  bring  the 
moon  so  close  that  he  could  see  thereon  trees,  houses, 
animals,  and  men-like  human  beings.  He  could  even 
discern  their  movements,  arid  gestures  that  indicated  a 
peaceful  race.  The  extent  of  the  hoax  will  be  perceived 
when  it  is  stated  that  no  telescope  that  we  are  now  able 
to  make  reveals  the  moon  more  clearly  than  it  would 
appear  to  the  naked  eye  if  it  was  one  hundred  or  one 
hundred  and  fifty  miles  away.  The  distance  at  which 
a  man  can  be  seen  by  the  unaided  eye  varies  according 
to  circumstances  of  position,  background,  light,  and  eye, 
but  it  is  much  inside  of  five  miles. 

Since,  however,  the  moon  is  our  nearest  neighbor,  a 
member  of  our  own  family  in  fact,  it  is  a  most  interest- 
ing object  of  study. 

A  glance  at  its  familiar  face  reveals  its  unequal  illu- 
mination. All  ages  and  races  have  seen  a  man  in  the 
moon.  All  lovers  have  sworn  by  its  constancy,  and 
only  part  of  them  have  kept  their  oaths.  Every  twenty- 
nine  or  thirty  days  we  see  a  silver  crescent  in  the  west, 
and  are  glad  if  it  comes  over  the  right  shoulder — so 


152  A   SOLAR  SYSTEM. 

much  tribute  does  habit  pay  to  superstition.  The  next 
night  it  is  thirteen  degrees  farther  east  from  the  sun. 
We  note  the  stars  it  occults,  or  passes  by,  and  leaves  be- 
hind as  it  broadens  its  disk,  till  it  rises  full-orbed  in  the 
east  when  the  sun  sinks  in  the  west.  It  is  easy  to  see 
that  the  moon  goes  around  the  earth  from  west  to  east. 
Afterward  it  rises  later  and  smaller  each  night,  till  at 
length,  lost  from  sight,  it  rises  about  the  same  time  as 
the  sun,  and  soon  becomes  the  welcome  crescent  new 
moon  again. 

The  same  peculiarities  are  always  evident  in  the  visi- 
ble face  of  the  moon;  hence  we  know  that  it  always 
presents  the  same  side  to  the  earth.  Obviously  it  must 
make  just  one  axial  to  one  orbital  revolution.  Hold 
any  body  before  you  at  arm's -length,  revolve  it  one- 
quarter  around  you  until  exactly  overhead.  If  it  has 
not  revolved  on  an  axis  between  the  hands,  another 
quarter  of  the  surface  is  visible;  but  if  in  going  up  it  is 
turned  a  quarter  over,  by  the  hands  holding  it  steady, 
the  same  side  is  visible.  Three  causes  enable  us  to 
see  a  little  more  than  half  the  moon's  surface :  1.  The 
speed  with  which  it  traverses  the  ellipse  of  its  orbit  is 
variable.  It  sometimes  gets  ahead  of  us,  sometimes  be- 
hind, and  we  see  farther  around  the  front  or  back  part. 
2.  The  axis  is  a  little  inclined  to  the  plane  of  its  orbit, 
and  its  orbit  a  little  inclined  to  ours;  hence  we  see  a 
little  over  its  north  pole,  and  then  again  over  the  south 
pole.  3.  The  earth  being  larger,  its  inhabitants  see  a 
little  more  than  half-way  around  a  smaller  body.  These 
causes  combined  enable  us  to  see  fVtnr  of  the  moon's 
surface.  Our  eyes  will  never  see  the  other  side  of  the 
moon.  If,  now,  being  solid,  her  axial  revolution  could 


THE  MOON.  153 

be  increased  enough  to  make  one  more  revolution  in 
two  or  three  years,  that  difference  between  her  axial 
and  orbital  revolution  would  give  the  future  inhabitants 
of  the  earth  a  view  of  the  entire  circumference  of  the 
moon.  Yet  if  the  moon  were  once  in  a  fluid  state,  or 
had  oceans  on  the  surface,  the  enormous  tide  caused  by 
the  earth  would  produce  friction  enough,  as  they  moved 
over  the  surface,  to  gradually  retard  the  axial  revolution 
till  the  two  tidal  elevations  remained  fixed  toward  and 
opposite  the  earth,  and  then  the  axial  and  orbital  revo- 
lutions would  correspond,  as  at  present.  In  fact,  we  can 
prove  that  the  form  of  the  moon  is  protuberant  toward 
the  earth.  Its  centre  of  gravity  is  thirty-three  miles  be- 
yond its  centre  of  magnitude,  which  is  the  same  in  ef- 
fect as  if  a  mountain  of  that  enormous  height  rose  on. 
the  earth  side.  Hence  any  fluid,  as  water  or  air,  would 
flow  round  to  the  other  side. 

The  moon's  day,  caused  by  the  sun's  light,  is  29j- 
times  as  long  as  ours.  The  sun  shines  unintermittingly 
for  fifteen  days,  raising  a  temperature  as  fervid  as  boil- 
ing water.  Then  darkness  and  frightful  cold  for  the 
same  time  succeed,  except  on  that  half  where  the  earth 
acts  as  a  moon.  The  earth  presents  the  same  phases — 
crescent,  full,  and  gibbons — to  the  moon  as  the  moon 
does  to  us,  and  for  the  same  causes.  Lord  Kosse  has 
been  enabled,  by  his  six-foot  reflector,  to  measure  the 
difference  of  heat  on  the  moon  under  the  full  blaze  of 
its  noonday  and  midnight.  He  finds  it  to  be  no  less 
than  five  hundred  degrees.  People  not  enjoying  ex- 
tremes of  temperature  should  shun  a  lunar  residence. 
The  moon  gives  us  only  fe  ^  8f0  0  0  as  much  light  as  the  sun. 
A  sky  full  of  moons  would  scarcely  make  daylight. 


154:  A   SOLAR  SYSTEM. 

There  are  no  indications  of  air  or  water  on  the  moon. 
When  it  occults  a  star  it  instantly  shuts  off  the  light 


Pig.  58.— View  of  the  Moon  near  the  Third  Quarter.    From  a  Photograph  by 
Professor  Heury  Draper. 

and  as  instantly  reveals  it  again.    An  atmosphere  would 
gradually  diminish  and  reveal  the  light,  and  by  refrac- 


THE  MOOX.  155 

tion  cause  the  star  to  be  bidden  in  much  less  time  than 
the  solid  body  of  the  moon  would  need  to  pass  over  it. 
If  the  moon  ever  had  air  and  water,  as  it  probably  did, 
they  are  now  absorbed  in  the  porous  lava  of  its  sub- 
stance. 

Telescopic  Appearance. 

Probably  no  one  ever  saw  the  moon  by  means  of  a 
good  telescope  without  a  feeling  of  admiration  and  awe. 
Except  at  full-moon,  we  can  see  where  the  daylight 
struggles  with  the  dark  along  the  line  of  the  moon's 
sunrise  or  sunset.  This  line  is  called  the  terminator. 
It  is  broken  in  the  extreme,  because  the  surface  is  as 
rough  as  possible.  In  consequence  of  the  small  gravita- 
tion of  the  moon,  utter  absence  of  the  expansive  power 
of  ice  shivering  the  cliffs,  or  the  levelling  power  of  rains, 
precipices  can  stand  in  perpendicularity,  mountains 
shoot  up  like  needles,  and  cav- 
ities three  miles  deep  remain 
unfilled.  The  light  of  the 
sun  falling  on  the  rough  body 
of  the  moon,  shown  in  sec- 
tion (Fig.  59),  illuminates  the  Fig.59.-Illumination  of  Craters  and 

whole  cavity  at  #,  part  of  the  Peaks- 

one  at  &,  casts  a  long  shadow  from  the  mountain  at  c,  and 
touches  the  tip  of  the  one  at  d,  which  appears  to  a  distant 
observer  as  a  point  of  light  beyond  the  terminator.  As 
the  moon  revolves  the  conical  cavity,  a  is  illuminated 
on  the  forward  side  only;  the  light  creeps  down  the 
backward  side  of  cavity  b  to  the  bottom ;  mountain  o 
comes  directly  under  the  sun  and  casts  no  shadow,  and 
mountain  d  casts  its  long  shadow  over  the  plain.  Know- 
ing the  time  of  revolution,  and  observing  the  change  of 


156 


A   SOLAR  SYSTEM. 


illumination,  we  can  easily  measure  the  height  of  moun- 
tain and  depth  of  crater.  An  apple,  with  excavations 
and  added  prominences,  revolved  on  its  axis  toward  the 


Fig.  CO. — Lunar  Crater  "Copernicus,''  after  Secchi. 

light  of  a  candle,  admirably  illustrates  the  crescent  light 
that  fills  either  side  of  the  cavities  and  the  shadows  of 
the  mountains  on  the  plain.  Notice  in  Fig.  58  the  cres- 
cent forms  to  the  right,  showing  cavities  in  abundance. 
The  selenography  of  one  side  of  the  moon  is  much 
better  known  to  us  than  the  geography  of  the  earth. 
Our  maps  of  the  moon  are  far  more  perfect  than  those 
of  the  earth ;  and  the  photographs  of  lunar  objects  by 
Messrs.  Draper  and  De  la  Rue  are  wonderfully  perfect, 


ECLIPSES.  157 

and  the  drawings  of  Padre  Secchi  equally  so  (Fig.  60). 
The  least  change  recognizable  from  the  earth  must  be 
speedily  detected.  There  are  frequently  reports  of  dis- 
coveries of  volcanoes  on  the  moon,  but  they  prove  to  be 
illusions.  The  moon  will  probably  look  the  same  to 
observers  a  thousand  years  hence  as  it  does  to-day. 

This  little  orb,  that  is  only  -£T  of  the  mass  of  the  earth, 
has  twenty-eight  mountains  that  are  higher  than  Mont 
Blanc,  that  "  monarch  of  mountains,"  in  Europe. 

Eclipses. 

It  is  evident  that  if  the  plane  of  the  moon's  orbit  were 
to  correspond  with  that  of  the  earth,  as  they  all  lie  in 
the  plane  of  the  page  (Fig.  61),  the  moon  must  pass 
between  the  centres  of  the  earth  and  sun,  and  exactly 


Fig.  61.— Eclipses ;  Shadows  of  Earth  aud  Moou. 

behind  the  earth  at  every  revolution.  Such  successive 
and  total  darkenings  would  greatly  derange  all  affairs 
dependent  on  light.  It  is  easily  avoided.  Venus  does 


158  A   SOLAR  .SYSTEM. 

not  cross  the  disk  of  the  sun  at  every  revolution,  be- 
cause of  the  inclination  of  the  plane  of  its  orbit  to  that 
of  the  earth  (see  Fig.  41,  p.  107).  So  the  plane  of  the 
orbit  of  the  moon  is  inclined  to  the  orbit  of  the  earth 
5°  8'  39" ;  hence  the  full-moon  is  often  above  or  below 
the  earth's  shadow,  and  the  earth  is  below  or  above  the 
moon's  shadow  at  new  moon.  It  is  as  if  the  moon's  or- 
bit were  pulled  up  one-quarter  of  an  inch  from  the  page 
behind  the  earth,  and  depressed  as  much  below  it  be- 
tween the  earth  and  the  sun.  The  point  where  the  or- 
bit of  the  moon  penetrates  the  plane  of  the  ecliptic  is 
called  a  node.  If  a  new  moon  occur  when  the  line  of 
intersection  of  the  planes  of  orbits  points  to  the  sun, 
the  sun  must  be  eclipsed ;  if  the  full-moon  occur,  the 
moon  must  be  eclipsed.  In  any  other  position  the  sun 
or  moon  will  only  be  partially  hidden,  or  no  eclipse  will 
occur. 

If  the  new  moon  be  near  the  earth  it  will  completely 
obscure  the  sun.  A  dime  covers  it  if  held  close  to  the 
eye.  It  may  be  so  far  from  the  earth  as  to  only  par- 
tially hide  the  sun ;  and,  if  it  cover  the  centre,  leave  a 
ring  of  sunlight  on  every  side.  This  is  called  an  annu- 
lar eclipse.  Two  such  eclipses  will  occur  this  year  (1879). 
If  the  full-moon  passes  near  the  earth,  or  is  at  perigee, 
it  finds  the  cone  of  shadow  cast  by  the  earth  larger,  and 
hence  the  eclipse  is  greater ;  if  it  is  far  from  the  earth, 
or  near  apogee,  the  earth's  shadow  is  smaller,  and  the 
eclipse  less,  or  is  escaped  altogether. 

There  is  a  certain  periodicity  in  eclipses.  Whenever 
the  sun,  moon,  and  earth  are  in  a  line,  as  in  the  total 
eclipse  of  July  29th,  1878,  they  will  be  in  the  same  po- 
sition after  the  earth  has  made  about  eighteen  revolu- 


MARS.  159 

tions,  and  the  moon  two  hundred  and  thirty-five — that 
is,  eighteen  years  after.  This  period,  however,  is  disre- 
garded by  astronomers,  and  each  eclipse  calculated  by 
itself  to  the  accuracy  of  a  second. 

How  terrible  is  the  fear  of  ignorance  and  superstition 
when  the  sun  or  moon  appear  to  be  in  the  process  of 
destruction !  how  delightful  are  the  joys  of  knowledge 
when  its  prophesies  in  regard  to  the  heavenly  bodies  are 
being  fulfilled ! 

MARS. 

The  god  of  war;  its  sign  $,  spear  aud  shield. 

Mean  distance  from  the  sun,  141,000,000  miles.  Diame- 
ter, 4211  miles.  Revolution,  axial,  24h.  37m.  22.7s. ;  orbital, 
686.98  days.  Velocity  per  minute,  899  miles.  Satellites,  two. 

At  intervals,  on  an  average  of  two  years  one  month 
and  nineteen  days,  we  find  rising,  as  the  sun  goes  down, 
the  reddest  star  in  the  heavens.  Its  brightness  is  ex- 
ceedingly variable;  sometimes  it  scintillates,  and  some- 
times it  shines  with  a  steady  light.  Its  marked  pecu- 
liarities demand  a  close  study.  We  find  it  to  be  Mars, 
the  fiery  god  of  war.  Its  orbit  is  far  from  circular.  At 
perihelion  it  is  128,000,000  miles  from  the  sun,  and  at 
aphelion  151,000,000 ;  hence  its  mean  distance  is  about 
141,000,000.  So  great  a  change  in  its  distance  from 
the  sun  partly  accounts  for  the  change  in  its  brilliancy. 
Now,  if  Mars  and  the  earth  revolved  in  circular  orbits, 
the  one  141,000,000  miles  from  the  sun,  and  the  other 
92,000,000,  they  would  approach  at  opposition  within 
49,000,000  miles  of  each  other,  and  at  conjunction  be 
233,000,000  miles  apart.  But  Mars  at  perihelion  may 
be  only  128,000,000  miles  from  the  sun,  and  earth  at 


160  A   SOLAR  SYSTEM. 

aphelion  may  be  94,000,000  miles  from  the  sun.  They 
are,  then,  but  34,000,000  miles  apart.  This  favorable 
opportunity  occurs  about  once  in  seventy -nine  years. 
At  its  last  occurrence,  in  1877,  Mars  introduced  to  us 
his  two  satellites,  that  had  never  before  been  seen  by 
man.  In  consequence  of  this  greatly  varying  distance, 
the  apparent  size  of  Mars  differs  very  much  (Fig.  62). 


Fig.  62.— Apparent  Size  of  Mars  at  Mean  and  Extreme  Distances. 

Take  a  favorable  time  when  the  planet  is  near,  also  as 
near  overhead  as  it  ever  comes,  so  as  to  have  as  little 
atmosphere  as  possible  to  penetrate,  and  study  the  plan- 
et. The  first  thing  that  strikes  the  observer  is  a  daz- 
zling spot  of  wThite  near  the  pole  which  happens  to  be 
toward  him,  or  at  both  poles  when  the  planet  is  so  situ- 
ated that  they  can  be  seen.  When  the  north  pole  is 
turned  toward  the  sun  the  size  of  the  spot  sensibly  di- 
minishes, and  the  spot  at  the  south  pole  enlarges,  and 
vice  versa.  Clearly  they  are  ice-fields.  Hence  Mars  has 
water,  and  air  to  carry  it,  and  heat  to  melt  ice.  It  is 
winter  at  the  south  pole  when  Mars  is  farthest  from 
the  sun  ;  therefore  the  ice-fields  are  larger  than  at  the 
north  pole.  It  is  summer  at  the  south  pole  when  Mars 
is  nearest  the  sun.  Hence  its  ice-fields  grow  smaller 


SATELLITES  OF  MARS.  161 

than  those  of  the  north  pole  in  its  summer.  This  car- 
rying of  water  from  pole  to  pole,  and  melting  of  ice 
over  such  large  areas,  might  give  rise  to  uncomfortable 
currents  in  ocean  and  air ;  but  very  likely  an  inhabitant 
of  earth  might  be  transported  to  the  surface  of  Mars, 
and  be  no  more  surprised  at  what  he  observed  there 
than  if  he  went  to  some  point  of  the  earth  to  him  un- 
known. Day  and  night  would  be  nearly  of  the  same 
length  ;  winter  would  linger  longer  in  the  lap  of  spring ; 
summer  would  be  one  hundred  and  eighty -one  days 
long;  but  as  the  seas  are  more  intermingled  with  the 
land,  and  the  divisions  of  land  have  less  of  continental 
magnitude,  it  may  be  conjectured  that  Mars  might  be  a 
comfortable  place  of  residence  to  beings  like  men.  Per- 
haps the  greatest  surprise  to  the  earthly  visitor  would 
be  to  find  himself  weighing  only  four-tenths  as  much  as 
usual,  able  to  leap  twice  as  high,  and  lift  considerable 
bowlders. 

Satellites  of  Mars. 

The  night  of  August  llth,  1877,  is  famous  in  modern 
astronomy.  Mars  has  been  a  special  object  of  study  in 
all  ages ;  but  on  that  evening  Professor  Hall,  of  Wash- 
ington, discovered  a  satellite  of  Mars.  On  the  16th  it 
was  seen  again,  and  its  orbital  motion  followed.  On  the 
following  night  it  was  hidden  behind  the  body  of  the 
planet  when  the  observation  began,  but  at  the  calcu- 
lated time — at  four  o'clock  in  the  morning — it  emerged, 
and  established  its  character  as  a  true  moon,  and  not  a 
fixed  star  or  asteroid.  Blessings,  however,  never  come 
singly,  for  another  object  §oon  emerged  which  proved 
to  be  an  inner  satellite.  This  is  extraordinarily  near 


162  A   SOLAR  SYSTEM. 

the  planet — only  four  thousand  miles  from  the  surface 
— and  its  revolution  is  exceedingly  rapid.  The  shortest 
period  hitherto  known  is  that  of  the  inner  satellite  of 
Saturn,  22h.  37m.  The  inner  satellite  of  Mars  makes 
its  revolution  in  7h.  39m. — a  rapidity  so  much  surpass- 
ing the  axial  revolution  of  the  planet  itself,  that  it  rises 
in  the  west  and  sets  in  the  east,  showing  all  phases  of 
our  moon  in  one  night.  The  outer  satellite  is  12,572 
miles  from  Mars,  and  makes  its  revolution  in  30h.  18m. 
Its  diameter  is  six  and  a  quarter  miles ;  that  of  the  in- 
ner one  is  seven  and  a  half  miles.  This  can  be  esti- 
mated only  by  the  amount  of  light  given. 

ASTEROIDS. 

Already  discovered  (1879),  201.  Distances  from  the  sun, 
from  200,000,000  to  315,000,000  miles.  Diameters,  from  20 
to  400  miles.  Mass  of  all,  less  than  one-quarter  of  the  earth. 

The  sense  of  infinite  variety  among  the  countless 
number  of  celestial  orbs  has  been  growing  rapidly  upon 
us  for  half  a  century,  and  doubtless  will  grow  much 
more  in  half  a  century  to  come.  Just  as  we  paused  in 
the  consideration  of  planets  to  consider  meteors  and 
comets,  at  first  thought  so  different,  so  must  we  now 
pause  to  consider  a  ring  of  bodies,  some  of  which  are 
as  small  in  comparison  to  Jupiter,  the  next  planet,  as 
aerolites  are  compared  to  the  earth. 

In  1800  an  association  of  astronomers,  suspecting  that 
a  planet  might  be  found  in  the  great  distance  between 
Mars  and  Jupiter,  divided  the  zodiac  into  twenty-four 
parts,  and  assigned  one  part  to  each  astronomer  for 
a  thorough  search  ;  but,  before  their  organization  could 
•sommence  work,  Piazzi,  an  Italian  astronomer  of  Paler- 


ASTEROIDS.  1G3 

mo,  found  in  Taurus  a  star  behaving  like  a  planet.  In 
six  weeks  it  was  lost  in  the  rajs  of  the  sun.  It  was 
rediscovered  on  its  emergence,  and  named  Ceres.  In 
March,  1802,  a  second  planet  was  discovered  by  Olbers 
in  the  same  gap  between  Mars  and  Jupiter,  and  named 
Pallas.  Here  was  an  embarrassment  of  richness.  Ol- 
bers suggested  that  an  original  planet  had  exploded, 
and  that  more  pieces  could  be  found.  More  were 
found,  but  the  theory  is  exploded  into  more  pieces 
than  a  planet  could  possibly  be.  Up  to  1879  one 
hundred  and  ninety-two  have  been  discovered,  with  a 
prospect  of  more.  Between  1871-75  forty-five  were 
discovered,  showing  that  they  are  sought  for  with  great 
skill.  In  the  discovery  of  these  bodies,  our  American 
astronomers,  Professors  Watson  and  Peters,  are  without 
peers. 

Between  Mars  and  Jupiter  is  a  distance  of  some 
339,000,000  miles.  Subtract  35,000,000  miles  next  to 
Mars  and  50,000,000  miles  next  to  Jupiter,  and  there  is 
left  a  zone  254,000,000  miles  wide  outside  of  which  the 
asteroids  never  wander.  If  any  ever  did,  the  attraction 
of  Mars  or  Jupiter  may  have  prevented  their  return. 

Since  the  orbits  of  Mars  and  Jupiter  show  no  sign  of 
being  affected  by  these  bodies  for  a  century  past,  it  is 
probable  that  their  number  is  limited,  or  at  least  that 
their  combined  mass  does  not  approximate  the  size  of  a 
planet.  Professor  Newcomb  estimates  that  if  all  that 
are  now  discovered  were  put  into  one  planet,  it  would 
not  be  over  four  hundred  miles  in  diameter;  and  if  a 
thousand  more  should  exist,  of  the  average  size  of  those 
discovered  since  1850,  their  addition  would  not  increase 
the  diameter  to  more  than  five  hundred  miles. 


164  A  SOLAR  SYSTEM. 

That  all  these  bodies,  which  differ  from  each  other  in 
no  respect  except  in  brilliancy,  can  be  noted  and  fixed 
so  as  not  to  be  mistaken  one  for  another,  and  instantly 
recognized  though  not  seen  for  a  dozen  years,  is  one  of 
the  highest  exemplifications  of  the  accuracy  of  astro- 
nomical observation. 

JUPITER. 

The  king  of  the  gods ;  sign  v,  the  bird  of  Jove. 

Distance  from  the  sun,  perihelion,  457,000,000  miles;  aphe- 
lion, 503,000,000  miles.  Diameter,  equatorial,  87,500  miles; 
polar,  82,500  miles.  Volume,  1400  earths.  Mass,  213  earths. 
Axial  revolution,  9h.  55m.  20s.  Orbital  revolution,  11  years 
317  days.  Velocity,  483.6  miles  per  minute. 

Jupiter  rightly  wears  the  name  of  the  "giant  planet." 
His  orbit  is  more  nearly  circular  than  most  smaller 


Fig.  63.— Jupiter  as  seen  by  the  great  Washington  Telescope.     Drawn  by  Mr. 

Holden. 

planets.     He  could  not  turn  short  corners  with  facility. 
We  know  little  of  his  surface.     His  spots  and  belts  are 


SATELLITES  OF  JUPITER.  165 

changeable  as  clouds,  which  they  probably  are.  Some 
spots  may  be  slightly  self-luminous,  but  not  the  part  of 
the  planet  we  see.  It  is  covered  with  an  enormous 
depth  of  atmosphere.  Since  the  markings  in  the  belts 
move  about  one  hundred  miles  a  day,  the  Jovian  tem- 
pests are  probably  not  violent.  It  is,  however,  a  singu- 
lar and  unaccountable  fact,  as  remarked  by  Arago,  that 
its  trade-winds  move  in  an  opposite  direction  from  ours. 
Jupiter  receives  only  one  twenty-seventh  as  much  light 
and  heat  from  the  sun  as  the  earth  receives.  Its  lighter 
density,  being  about  that  of  water,  indicates  that  it  still 
has  internal  heat  of  its  own.  Indeed,  it  is  likely  that 
this  planet  has  not  yet  cooled  so  as  to  have  any  solid 
crust,  and  if  its  dense  vapors  could  be  deposited  on  the 
surface,  its  appearance  might  be  more  suggestive  of  the 
sun  than  of  the  earth. 

Satellites  of  Jupiter. 

In  one  respect  Jupiter  seems  like  a  minor  sun — he  is 
royally  attended  by  a  group  of  planets :  we  call  them 
moons.  This  system  is  a  favorite  object  of  study  to 
every  one  possessing  a  telescope.  Indeed,  I  have  known 
a  man  who  could  see  these  moons  with  the  naked  eye, 
and  give  their  various  positions  without  mistake.  Gali- 
leo first  revealed  them  to  ordinary  men.  We  see  their 
orbits  so  nearly  on  the  edge  that  the  moons  seem  to  be 
sliding  back  and  forth  across  and  behind  the  disk,  and 
to  varying  distances  on  either  side.  Fig.  64  is  the  rep- 
resentation of  their  appearance  at  successive  observa- 
tions in  November,  1878.  Their  motion  is  so  swift,  and 
the  means  of  comparison  by  one  another  and  the  planet 
so  excellent,  that  they  can  be  seen  to  change  their  places, 


166 


A   SOLAR  SYSTEM. 


Fig.  64. — a.  Various  Positions  of  Jupiter's  Moous ;  6.  Greatest  Elongation  of  eacb 

Satellite. 

be  occulted,  emerge  from  shadow,  and  eclipse  the  plan- 
et, in  an  hour's  watching. 

ELEMENTS    OF   JDPITER's   SATELLITES. 


Mean  Distance 
from  Jupiter. 

Sidereal  Period. 

Diameter. 

I.  lo  

Miles. 

260,000 

Days   Hrs.    Min. 
1      18      28 

Miles. 

2,352 

II    Europa           . 

414,000 

3    13    43 

2,01)!) 

Ill    Gnnvmede  

661,000 

7      3    59 

3,436 

IV    Callixto 

1,162,000 

16    18      5 

2  929 

It  is  seen  by  the  above  table  that  all  these  moons 
are  larger  than  ours,  one  larger  than  Mercury,  and  the 
asteroids  are  hardly  large  enough  to  make  respectable 
moons  for  them.  They  differ  in  color  :  I.  and  II.  have 
a  bluish  tinge ;  III.  a  yellow ;  and  IY.  is  red.  The 
amount  of  light  given  by  these  satellites  varies  in  the 
most  sudden  and  inexplicable  manner.  Perhaps  it  may 
be  owing  to  the  different  distributions  of  land  and  wa- 
ter on  them.  The  mass  of  all  of  them  is  .000171  of 
Jupiter. 


SATURN.  167 

If  the  Jovian  system  were  the  only  one  in  existence, 
it  would  be  a  surprising  object  of  wonder  and  study. 
A  monster  planet,  85,000  miles  in  diameter,  hung  on 
nothing,  revolving  its  equatorial  surface  over  450  miles 
a  minute,  holding  four  other  worlds  in  steady  orbits, 
some  of  them  at  a  speed  of  TOO  miles  a  minute,  and 
the  whole  system  carried  through  space  at  500  miles  a 
minute.  Yet  the  discovery  of  all  this  display  of  power, 
skill,  and  stability  is  only  reading  the  easiest  syllables 
of  the  vast  literature  of  wisdom  and  power. 

SATURN, 

The  god  of  time ;  sign  ? ,  his  scythe. 

Mean  distance  from  the  sun,  881,000,000  miles.  Diameter, 
polar,  66,500  miles;  equatorial,  73,300  miles.  Axial  revolu- 
tion, lOh.  14m.  Periodic  time,  29£  years.  Moons,  eight 

The  human  mind  has  used  Saturn  and  the  two  known 
planets  beyond  for  the  last  200  years  as  a  gymnasium. 
It  has  exercised  itself  in  comprehending  their  enormous 
distances  in  order  to  clear  those  greater  spaces,  to  where 
the  stars  a.re  set ;  it  has  exercised  its  ingenuity  at  inter- 
preting appearances  which  signify  something  other  than 
they  seem,  in  order  that  it  may  no  longer  be  deluded 
by  any  sunrises  into  a  belief  that  the  heavenly  dome 
goes  round  the  earth.  That  a  wandering  point  of  light 
should  develop  into  such  amazing  grandeurs  under  the 
telescope,  is  as  unexpected  as  that  every  tiny  seed  should 
show  peculiar  markings  and  colors  under  the  microscope. 

There  are  certain  things  that  are  easy  to  determine, 
such  as  size,  density,  periodic  time,  velocity,  etc. ;  but 
other  things  are  exceedingly  difficult  to  determine.  It 
requires  long  sight  to  read  when  the  book  is  held 


168  A   SOLAR  SYSTEM. 

800,000,000  miles  away.  Only  very  few,  if  more  than 
two,  opportunities  have  been  found  to  determine  the 
time  of  Saturn's  rotation.  On  the  evening  of  December 


Fig.  65.— View  of  Saturn  and  his  Rings. 

7th,  1870,  Professor  Hall -observed  a  brilliant  white  spot 
suddenly  show  itself  on  the  body  of  this  planet.  It  was 
as  if  an  eruption  of  white  hot  matter  burst  up  from  the 
interior.  It  spread  eastward,  and  remained  bright  till 
January,  when  it  faded.  No  such  opportunity  for  get- 
ting a  basis  on  which  to  found  a  calculation  of  the  time 
of  the  rotation  of  Saturn  has  occurred  since  Sir  William 
Herschel's  observations;  and,  very  singularly,  the  two 
times  deduced  wonderfully  coincide — that  of  Herschel 
being  lOh.  16m.,  that  of  Mr.  Hall  being  lOh.  Urn, 


SATURF'S  RINGS.  169 

The  density  of  Saturn  is  less  than  that  of  water,  and 
its  velocity  of  rotation  so  great  that  centrifugal  force 
antagonizes  gravitation  to  such  an  extent  that  bodies 
weigh  on  it  about  the  same  as  on  the  earth.  All  the 
fine  fancies  of  the  habitability  of  this  vaporous  world, 
all  the  calculations  of  the  number  of  people  that  could 
live  on  the  square  miles  of  the  planet  and  its  enormous 
rings,  are  only  fancy.  Nothing  could  live  there  with 
more  brains  than  a  fish,  at  most.  It  is  a  world  in  for- 
mative processes.  We  cannot  hear  the  voice  of  the 
Creator  there,  but  we  can  see  matter  responsive  to  the 
voice,  and  moulded  by  his  word. 

Rings  of  Saturn. 

The  eye  and  mind  of  man  have  worked  out  a  prob- 
lem of  marvellous  difficulty  in  finding  a  true  solution 
of  the  strange  appearance  of  the  rings.  Galileo  has 
the  immortal  honor  of  first  having  seen  something  pe- 
culiar about  this  planet.  He  wrote  to  the  Duke  of 
Tuscany,  "  When  I  view  Saturn  it  seems  tricorps.  The 
central  body  seems  the  largest.  The  two  others,  situated, 
the  one  on  the  east,  and  the  other  on  the  west,  seem  to 
touch  it.  They  are  like  two  supporters,  who  help  old 
Saturn  on  his  way,  and  always  remain  at  his  side." 
Looking  a  few  years  later,  the  rings  having  turned  from 
view,  he  said,  "  It  is  possible  that  some  demon  mocked 
me  ;"  and  he  refused  to  look  any  more. 

Huyghens,  in  March,  1655,  solved  the  problem  of  the 
triform  appearance  of  Saturn.  He  saw  them  as  han- 
dles on  the  two  sides.  In  a  year  they  had  disappeared, 
and  the  planet  was  as  round  as  it  seemed  to  Galileo  in 
1612.  He  did  not,  however,  despair ;  and  in  October, 

S 


170  A   SOLAR  SYSTEM. 

1656,  he  was  rewarded  by  seeing  them  appear  again. 
He  wrote  of  Saturn,  "  It  is  girdled  by  a  thin  plain  ring, 
nowhere  touching,  inclined  to  the  ecliptic." 

Since  that  time  discoveries  have  succeeded  one  an- 
other rapidly.  "  We  have  seen  by  degrees-a  ring  evolved 
out  of  a  triform  planet,  and  the  great  division  of  the 
ring  and  the  irregularities  on  it  brought  to  light.  En- 
celadus,  and  coy  Mimas,  faintest  of  twinklers,  are  caught 
by  Herschel's  giant  mirrors.  And  he,  too,  first  of  men, 
realizes  the  wonderful  tenuity  of  the  ring,  along  which 
he  saw  those  satellites  travelling  like  pearls  strung  on  a 
silver  thread.  Then  Bond  comes  on  the  field,  and  fur- 
nishes evidence  to  show  that  we  must  multiply  the 
number  of  separate  rings  we  know  not  how  many  fold. 
And  here  we  reach  the  golden  age  of  Saturnian  discov- 
ery, when  Bond,  with  the  giant  refractor  of  Cambridge, 
and  Dawes,  with  his  6^-inch  Munich  glass,  first  beheld 
that  wonderful  dark  semi-transparent  ring,  which  still 
remains  one  of  the  wonders  of  our  system.  But  the 
end  is  not  yet :  on  the  southern  surface  of  the  ring,  ere 
summer  fades  into  autumn,  Otto  Struve  in  turn  comes 
upon  the  field,  detects,  as  Dawes  had  previously  done,  a 
division  even  in  the  dark  ring,  and  measures  it,  while  it 
is  invisible  to  Lassell's  mirror — a  proof,  if  one  were  need- 
ed, of  the  enormous  superiority  possessed  by  refractors 
in  such  inquiries.  Then  we  approach  1861,  when  the 
ring  plane  again  passes  through  the  earth,  and  Struve 
and  Wray  observe  curious  nebulous  appearances."* 

Our  opportunities  for  seeing  Saturn  vary  greatly.  As 
the  earth  at  one  part  of  its  orbit  presents  its  south  pole 

*  Lockyer. 


SATURN1  S  RINGS.  171 

to  the  sun,  then  its  equator,  then  the  north  pole,  so  Sat- 
urn ;  and  we,  in  the  direction  of  the  sun,  see  the  south 
side  of  the  rings  inclined  at  an  angle  of  27° ;  next  the 
edge  of  the  rings,  like  a  fine  thread  of  light;  then  the 
north  side  at  a  similar  inclination.  On  February  7th, 
1878,  Saturn  was  between  Aquarius  and  Pisces,  with  the 
edge  of  the  ring  to  the  sun.  In  1885,  the  planet  be- 
ing in  Taurus,  the  south  side  of  the  rings  will  be  seen 
at  the  greatest  advantage.  From  1881  till  1885  all  cir- 
cumstances will  combine  to  give  most  favorable  studies 
of  Saturn.  Meanwhile  study  the  picture  of  it.  The 
outer  ring  is  narrow,  dark,  showing  hints  of  another  di- 
vision, sometimes  more  evident  than  at  others,  as  if  it 
were  in  a"  state  of  flux.  The  inner,  or  second,  ring  is 
much  brighter,  especially  on  the  outer  edge,  and  shading 
off  to  the  dusky  edge  next  to  the  planet.  There  is  no 
sign  of  division  into  a  third  dusky  innermost  ring,  as 
was  plainly  seen  by  Bond.  This,  too,  may  be  in  a  state 
of  flux. 

The  markings  of  the  planet  are  delicate,  difficult  of 
detection,  and  are  not  like  those  stark  zebra  stripes  that 
are  so  often  represented. 

The  distance  between  the  planet  and  the  second  ring 
seems  to  be  diminished  one-half  since  1657,  and  this 
ring  has  doubled  its  breadth  in  the  same  time.  Some 
of  this  difference  may  be  owing  to  our  greater  tele- 
scopic power,  enabling  us  to  see  the  ring  closer  to  the 
planet ;  but  in  all  probability  the  ring  is  closing  in  upon 
the  central  body,  and  will  touch  it  by  A.D.  2150.  Thus 
the  whole  ring  must  ultimately  fall  upon  the  planet, 
instead  of  making  a  satellite. 

We  are  anxious  to  learn  the  nature  of  such  a  ring. 


172  A   SOLAR  SYSTEM. 

Laplace  mathematically  demonstrated  that  it  cannot  be 
uniform  and  solid,  and  survive.  Professor  Peirce  show- 
ed it  could  not  be  fluid,  and  continue.  Then  Professor 
Maxwell  showed  that  it  must  be  formed  of  clouds  of 
satellites  too  small  to  be  seen  individually,  and  too  near 
together  for  the  spaces  to  be  discerned,  unless,  perhaps, 
we  may  except  the  inner  dark  ring,  where  they  are 
not  near  enough  to  make  it  positively  luminous.  In- 
deed, there  is  some  evidence  that  the  meteoroids  are  far 
enough  apart  to  make  the  ring  partially  transparent. 

We  look  forward  to  the  opportunities  for  observation 
in  1882  with  the  brightest  hope  that  these  difficult 
questions  will  be  solved. 

Satellites  of  Saturn. 

The  first  discovered  satellite  of  Saturn  seen  by 
Huyghens  was  in  1655,  and  the  last  by  the  Bonds,  fa- 
ther and  son,  of  Cambridge,  in  1848.  These  are  eight 
in  number,  and  are  named  : 

Distant  from  Saturn's  centre. 

I.  Mimas 119,725  miles. 

II.  Enceladus 153,630 

III.  Tethys 190,225 

IV.  Dione 243,670 

V.  Rhea 340,320 

VI.  Titan 788,915 

VII.  Hyperion 954,160 

VIII.  Japetus 2,292,790 

Titan  can  be  seen  by  almost  any  telescope ;  I.,  II.,  and 
VII.,  only  by  the  most  powerful  instrument.  All  ex- 
cept Japetus  revolve  nearly  in  the  plane  of  the  ring. 
Like  the  moons  of  Jupiter,  they  present  remarkable  and 
unaccountable  variations  of  brilliancy.  An  inspection 


URANUS.  173 

of  the  table  reveals  either  an  expectation  that  another 
moon  will  be  discovered  between  Y.  and  YL,  and  about 
three  more  between  YII.  and  YIIL,  or  that  these  gaps 
may  be  filled  with  groups  of  invisible  asteroids,  as  the 
gap  between  Mars  and  Jupiter.  This  will  become  more 
evident  by  drawing  Saturn,  the  rings,  and  orbits  of 
the  moons  all  as  circles,  on  a  scale  of  10,000  miles  to 
the  inch.  Saturn  will  be  in  the  centre,  70,000  miles  in 
diameter;  then  a  gap,  decreasing  twenty -nine  miles 
a  year  to  the  first  ring,  of,  say,  10,000  miles ;  a  dark 
ring  9000  miles  wide;  next  the  brightest  ring  18,300 
miles  wide;  then  a  gap  of  1750  miles;  then  the  outer 
ring  10,000  miles  wide ;  then  the  orbits  of  the  satellites 
in  order. 

If  the  scenery  of  Jupiter  is  magnificent,  that  of  Saturn 
must  be  sublime.  If  one  could  exist  there,  he  might 
wander  from  the  illuminated  side  of  the  rings,  under 
their  magnificent  arches,  to  the  darkened  side,  see  the 
swift  whirling  moons;  one  of  them  presenting  ten  times 
the  disk  of  the  earth's  moon,  and  so  very  near  as  to  en- 
able him  to  watch  the  advancing  line  of  light  that  marks 
the  lunar  morning  journeying  round  that  orb. 

URANUS. 

Sign  Jjl ;  the  initial  of  Herechel,  and  sign  of  the  world. 

Distance  from  the  sun,  1, 771,000,000  miles.  Diameter,  31,700 
miles.  Axial  revolution  unknown.  Orbital,  84  years.  Ve- 
locity per  minute,  252  miles.  Moons,  four. 

Uranus  was  presented  to  the  knowledge  of  man  as 
an  unexpected  reward  for  honest  work.  It  was  first 
mistaken  by  its  discoverer  for  a  comet,  a  mere  cloud  of 
vapor ;  but  it  proved  to  be  a  world,  and  extended  the 


174  A   SOLAR  SYSTEM. 

boundaries  of  our  solar  system,  in  the  moment  of  its 
discovery,  as  much  as  all  investigation  had  done  in  all 
previous  ages. 

Sir  William  Herschel  was  engaged  in  mapping  stars 
in  1781,  when  he  first  observed  its  sea-green  disk.  He 
proposed  to  call  it  Georgium  Sidus,  in  honor  of  his 
king ;  but  there  were  too  many  names  of  the  gods  in 
the  sky  to  allow  a  mortal  name  to  be  placed  among 
them.  It  was  therefore  called  Uranus,  since,  being  the 
most  distant  body  of  our  system,  as  was  supposed,  it 
might  appropriately  bear  the  name  of  the  oldest  god. 
Finding  anything  in  God's  realms  of  infinite  riches 
ought  not  to  lead  men  to  regard  that  as  final,  but  as  a 
promise  of  more  to  follow. 

This  planet  had  been  seen  five  times  by  Flamsteed 
before  its  character  was  determined — once  nearly  a  cen- 
tury before— and  eight  times  by  Le  Monnier.  These 
names,  which  might  easily  have  been  associated  with  a 
grand  discovery,  are  associated  with  careless  observa- 
tion. Eyes  were  made  not  only  to  be  kept  open,  but 
to  have  minds  behind  them  to  interpret  their  visions. 
"Herschel  thought  he  discovered  six  moons  belonging 
to  Uranus,  but  subsequent  investigation  has  limited  the 
number  to  four.  Two  of  these  are  seen  with  great  dif- 
ficulty by  the  most  powerful  telescopes. 

If  the  plane  of  our  moon's  orbit  were  tipped  up  to 
a  greater  inclination,  revolving  it  on  the  line  of  nodes 
as  an  axis  until  it  was  turned  85°,  the  moon,  still  con- 
tinuing on  its  orbit  in  that  plane,  would  go  over  the 
poles  instead  of  about  the  equator,  and  would  go  back 
to  its  old  path  when  the  plane  was  revolved  180° ;  but 
its  revolution  would  now  be  from  east  to  west,  or  ret- 


NEPTUNE.  175 

rograde.  The  plane  of  the  moons  of  Uranus  has  been 
thus  inclined  till  it  has  passed  10°  beyond  the  pole, 
and  the  moons'  motions  are  retrograde  as  regards  other 
known  celestial  movements.  How  Uranus  itself  revolves 
is  not  known.  There  are  more  worlds  to  conquer. 

NEPTUNE. 

God  of  the  sea ;  sign  £!,  his  trideut. 

Distance  from  the  sun,  2, 775,000, OOO  miles.  Diameter, 
34,500  miles.  Velocity  per  minute,  201.6  miles.  Axial  rev- 
olution unknown.  Orbital,  164.78  years.  One  moon. 

Men  sought  for  Neptune  as  the  heroes  sought  the 
golden  fleece.  The  place  of  Uranus  had  been  mapped 
for  nearly  one  hundred  years  by  these  accidental  ob- 
servations. On  applying  the  law  of  universal  gravita- 
tion, a  slight  discrepancy  was  found  between  its  com- 
puted place  and  its  observed  place.  This  discrepancy 
was  exceedingly  slight.  In  1830  it  was  only  20";  in 
1840,  90";  in  1844,  2'.  Two  stars  that  were  2'  apart 
would  appear  as  one  to  the  keenest  unaided  eye,  but  sucli 
an  error  must  not  exist  in  astronomy.  Years  of  work 
were  given  to  its  correction.  Mr.  John  C.  Adams,  of 
Cambridge,  England,  finding  that  the  attraction  of  a 
planet  exterior  to  Uranus  would  account  for  its  irregu- 
larities, computed  the  place  of  such  a  hypothetical  body 
with  singular  exactness  in  October,  1841 ;  but  neither 
he  nor  the  royal  astronomer  Airy  looked  for  it.  An- 
other opportunity  for  immortality  was  heedlessly  neg- 
lected. Meanwhile,  M.  Leverrier,  of  Paris,  was  working 
at  the  same  problem.  In  the  summer  of  1846  Lever- 
rier announced  the  place  of  the  exterior  planet.  The 
conclusion  was  in  striking  coincidence  with  that  of  Mr. 


17G 


A  SOLAR  SYSTEM. 


et  is  understood  from  Fig.  66. 


Adams.  Mr.Challis  commenced  to  search  for  the  planet 
near  the  indicated  place,  and  actually  saw  and  mapped 
the  star  August  4th,  1846,  but  did  not  recognize  its 
planetary  character.  Dr.  Galle,  of  Berlin,  on  the  23d 
of  September,  1846,  found  an  object  with  a  planetary 
disk  .not  plotted  on  the  map  of  stars.  It  was  the 
sough t-f or  world.  It  would  seem  easy  to  find  a  world 
seventy-six  times  as  large  as  the  earth,  and  easy  to  rec- 
ognize it  when  seen.  The  fact  that  it  could  be  discov- 
ered only  by  such  care  conveys  an  overwhelming  idea 
of  the  distance  where  it  moves. 

The  effect  of  these  perturbations  by  an  exterior  plan- 
Uranus  and  Neptune 
were  i  in  conjunction,  as 
shown,  in  1822.  But  in 
1820  it  had  been  found 
that  Uranus  was  too  far 
from  the  sun,  and  too  much 
accelerated.  Since  1800, 
Neptune,  in  his  orbit  from 
F  to  E,  had  been  hasten- 
ing Uranus  in  his  orbit 
from  C  to  B,  and  also 
Fig.  eo.-pertnrbati.rn  of  Uranus.  drawing  it  farther  from 

the  sun.  After  1822,  Neptune,  in  passing  from  E  to  D, 
had  been  retarding  Uranus  in  his  orbit  from  B  to  A. 

We  have  seen  it  is  easy  to  miss  immortality.  There 
is  still  another  instance.  Lalande  saw  Neptune  on 
May  8th  and  10th,  1795,  noted  that  it  had  moved  a  lit- 
tle, and  that  the  observations  did  not  agree  ;  but,  suppos- 
ing the  first  was  wrong,  carelessly  missed  the  glory  -of 
once  more  doubling  the  bounds  of  the  empire  of  the  sun. 


NEPTUNE.  177 

It  is  time  to  pause  and  review  our  knowledge  of  this 
system.  The  first  view  reveals  a  moon  and  earth  en- 
dowed with  a  force  of  inertia  going  on  in  space  in 
straight  lines ;  but  an  invisible  elastic  cord  of  attraction 
holds  them  together,  just  counterbalancing  this  tenden- 
cy to  fly  apart,  and  hence  they  circle  round  their  centre 
of  gravity.  The  revolving  earth  turns  every  part  of  its 
surface  to  the  moon  in  each  twenty-five  hours.  By  an 
axial  revolution  in  the  same  time  that  the  moon  goes 
round  the  earth,  the  moon  holds  the  same  point  of  its 
surface  constantly  toward  the  earth.  If  we  were  to  add 
one,  two,  four,  eight  moons  at  appropriate  distances,  the 
result  would  be  the  same.  There  is,  however,  another 
attractive  influence — that  of  the  sun.  The  sun  attracts 
both  earth  and  moon,  but  their  nearer  affection  for 
each  other  keeps  them  from  going  apart.  They  both, 
revolving  on  their  axes  and  around  their  centre  of  grav- 
ity, sweep  in  a  vastly  wider  curve  around  the  sun.  Add 
as  many  moons  as  has  Jupiter  or  Saturn,  the  result  is 
the  same — an  orderly  carrying  of  worlds  through  space. 

There  lies  the  unsupported  sun  in  the  centre,  nearer 
to  infinity  in  all  its  capacities  and  intensities  of  force  than 
our  minds  can  measure,  filling  the  whole  dome  to  where 
the  stars  are  set  with  light,  heat,  and  power.  It  holds 
five  small  worlds — Vulcan,  Mercury,  Yenus,  Earth,  and 
Mars — within  a  space  whose  radius  it  would  require  a 
locomotive  half  a  thousand  years  to  traverse.  It  next 
holds  some  indeterminate  number  of  asteroids,  and  the 
great  Jupiter,  equal  in  volume  to  1400  earths.  It 
holds  Saturn,  Uranus,  and  Neptune,  and  all  their  various- 
ly related  satellites  and  rings.  The  two  thoughts  that 
overwhelm  us  are  distance  and  power.  The  period  of 

8* 


178  A   SOLAR  SYSTEM. 

man's  whole  history  is  not  sufficient  for  an  express  train 
to  traverse  half  the  distance  to  Neptune.  Thought  wea- 
ries and  fails  in  seeking  to  grasp  such  distances ;  it  can 
scarcely  comprehend  one  million  miles,  and  here  are 
thousands  of  them.  Even  the  wings  of  imagination 
grow  weary  and  droop.  When  we  stand  on  that  outer- 
most of  planets,  the  very  last  sentinel  of  the  outposts  of 
the  king,  the  very  sun  grown  dim  and  small  in  the  dis- 
tance, we  have  taken  only  one  step  of  the  infinite  dis- 
tance to  the  stars.  They  have  not  changed  their  rela- 
tive position — they  have  not  grown  brighter  by  our  ap- 
proach. Neptune  carries  us  round  a  vast  circle  about 
the  centre  of  the  dome  of  stars,  but  we  seem  no  nearer 
its  sides.  In  visiting  planets,  we  have  been  only  visiting 
next-door  neighbors  in  the  streets  of  a  seaport  town. 
We  know  that  there  are  similar  neighbors  about  Sirius 
and  Arcturus,  but  a  vast  sea  rolls  between.  As  we  said, 
we  stand  with  the  outermost  sentinel ;  but  into  the  great 
void  beyond  the  king  of  day  sends  his  comets  as  scouts, 
and  they  fly  thousands  of  years  without  for  one  instant 
missing  the  steady  grasp  of  the  power  of  the  sun.  It  is 
nearer  alrnightiness  than  we  are  able  to  think. 

If  we  cannot  solve  the  problems  of  the  present  exist- 
ence of  worlds,  how  little  can  we  expect  to  fathom  the 
unsoundable  depths  of  their  creation  and  development 
through  ages  measureless  to  man  !  Yet  the  very  diffi- 
culty provokes  the  most  ambitious  thought.  We  toil 
at  the  problem  because  it  has  been  hitherto  unsolvable. 
Every  error  we  make,  and  discover  to  be  such,  helps 
toward  the  final  solution.  Every  earnest  thinker  who 
climbs  the  shining  worlds  as  steps  to  a  higher  thought 
is  trying  to  solve  the  problem  God  has  given  us  to  do. 


ix:. 

THE  NEBULAR  HYPOTHESIS. 

"And  the  earth  was  without  form,  and  void;  and  darkness  was  upon 
the  face  of  the  deep." — Genesis  i.  2. 


"A  dark 

Illimitable  ocean,  without  bound, 

Without  dimension,  where  length,  breadth,  and  height, 
And  time,  and  place  are  lost." — MILTON. 

*vlt  is  certain  that  matter  is  somehow  directed,  controlled,  and  ar- 
ranged ;  while  no  material  forces  or  properties  are  known  to  be  capable 
of  discharging  such  functions." — LIONEL  BEALE. 

"The  laws  of  nature  do  not  account  for  their  own  origin." — JOHN 
STUART  MILL. 


THE  NEBULAR  HYPOTHESIS.  181 


IX. 
THE  NEBULAR  HYPOTHESIS. 

THE  method  by  which  the  solar  system  came  into  its 
present  form  was  sketched  in  vast  outline  by  Moses, 
lie  gave  us  the  fundamental  idea  of  what  is  called 
the  nebular  hypothesis.  Swedenborg,  that  prodigal 
dreamer  of  vagaries,  in  1734  threw  out  some  conject- 
ures of  the  way  in  which  the  outlines  were  to  be  filled 
up  ;  Buffon  followed  him  closely  in  1749  ;  Kant  sought 
to  give  it  an  ideal  philosophical  completeness,  as  he  said, 
"  not  as  the  result  of  observation  and  computation,"  but 
as  evolved  out  of  his  own  consciousness ;  and  Laplace 
sought  to  settle  it  on  a  mathematical  basis. 

It  has  been  modified  greatly  by  later  writers,  and 
must  receive  still  greater  modifications  before  it  can  be 
accepted  by  the  best  scientists  of  to-day.  It  has  been 
called  "  the  grandest  generalization  of  the  human  mind ;" 
and  if  it  shall  finally  be  so  modified  as  to  pass  from  a 
tentative  hypothesis  to  an  accepted  philosophy,  declar- 
ing the  modes  of  a  divine  worker  rather  than  the  neces- 
sities of  blind  force,  it  will  still  be  worthy  of  that  high 
distinction. 

Let  it  be  clearly  noted  that  it  never  proposes  to  do 
more  than  to  trace  a  portion  of  the  mode  of  working 
which  brought  the  universe  from  one  stage  to  another. 
It  only  goes  back  to  a  definite  point,  never  to  absolute 
beginning,  nor  to  nothingness.  It  takes  matter  from 


182  THE  NEBULAR  HYPOTHESIS. 

the  hand  of  the  unseen  power  behind,  and  merely  notes 
the  progress  of  its  development.  It  finds  the  clay  in 
the  hands  of  an  intelligent  potter,  and  sees  it  whirl  in 
the  process  of  formation  into  a  vessel.  It  is  not  in  any 
sense  necessarily  atheistic,  any  more  than  it  is  to  affirm 
that  a  tree  grows  by  vital  processes  in  the  sun  and  dew, 
instead  of  being  arbitrarily  and  instantly  created.  The 
conclusion  reached  depends  on  the  spirit  of  the  ob- 
server. Newton  could  say,  "This  most  beautiful  system 
of  the  sun,  planets,  arid  comets  could  only  proceed  from 
the  counsel  and  dominion  of  an  intelligent  and  power- 
ful being !"  Still  it  is  well  to  recognize  that  some  of  its 
most  ardent  defenders  have  advocated  it  as  materialis- 
tic. And  Laplace  said  of  it  to  Napoleon,  "  I  have  no 
need  of  the  hypothesis  of  a  god." 

The  materialistic  statement  of  the  theory  is  this :  that 
matter  is  at  first  assumed  to  exist  as  an  infinite  cloud 
of  fire-mist,  dowered  with  power  latent  therein  to  grow 
of  itself  into  every  possibility  of  world,  flower,  animal, 
man,  mind,  and  affection,  without  any  interference  or 
help  from  without.  But  it  requires  far  more  of  the  Di- 
vine Worker  than  any  other  theory.  He  must  fill  mat- 
ter with  capabilities  to  take  care  of  itself,  and  this  would 
tax  the  abilities  of  the  Infinite  One  far  more  than  a  con- 
stant supervision  and  occasional  interference.  Instead 
of  making  the  vase  in  perfect  form,  and  coloring  it  with 
exquisite  beauty  by  an  ever-present  skill,  he  must  en- 
dow the  clay  with  power  to  make  itself  in  perfect  form, 
adorn  itself  with  delicate  beauty,  and  create  other  vases. 

The  nebular  hypothesis  is  briefly  this :  All  the  mat- 
ter composing  all  the  bodies  of  the  sun,  planets,  and 
satellites  once  existed  in  an  exceedingly  diffused  state ; 


THE  NEBULAR  HYPOTHESIS.  183 

rarer  than  any  gas  with  which  we  are  acquainted,  filling 
a  space  larger  than  the  orbit  of  Xeptune.  Gravitation 
gradually  contracted  this  matter  into  a  condensing  globe 
of  immense  extent.  Some  parts  would  naturally  be 
denser  than  others,  and  in  the  course  of  contraction  a 
rotary  motion,  it  is  affirmed,  would  be  engendered.  Ro- 
tation would  flatten  the  globe  somewhat  in  the  line  of 
its  axis.  Contracting  still  more,  the  rarer  gases,  aided 
by  centrifugal  force,  would  be  left  behind  as  a  ring  that 
would  ultimately  be  separated,  like  Saturn's  ring,  from 
the  retreating  body.  There  would  naturally  be  some 
places  in  this  ring  denser  than  others ;  these  would  grad- 
ually absorb  all  the  ring  into  a  planet,  and  still  revolve 
about  the  central  mass,  and  still  rotate  on  its  own  axis, 
throwing  off  rings  from  itself.  Thus  the  planet  Xep- 
tune  would  be  left  behind  in  the  first  sun-ring,  to  make 
its  one  moon ;  the  planet  Uranus  left  in  the  next  sun- 
ring,  to  make  its  four  moons  from  four  successive  plan- 
et-rings ;  Saturn,  with  its  eight  moons  and  three  rings 
not  made  into  moons,  is  left  in  the  third  sun-ring;  and 
so  on  down  to  Yulcan. 

The  outer  planets  would  cool  off  first,  become  inhab- 
itable, and,  as  the  sun  contracted  and  they  radiated  their 
own  heat,  become  refrigerated  and  left  behind  by  the 
retreating  sun.  Of  course  the  outer  planets  would 
move  slowly;  but  as  that  portion  of  the  sun  which  gave 
them  their  motion  drew  in  toward  the  centre,  keeping 
its  absolute  speed,  and  revolving  in  the  lessening  circles 
of  a  contracting  body,  it  would  give  the  faster  motion 
necessary  to  be  imparted  to  Earth,  Mercury,  and  Yulcan. 

The  four  great  classes  of  facts  confirmatory  of  this 
hypothesis  are  as  follows :  1st.  All  the  planets  move 


184  THE  NEBULAR  HYPOTHESIS. 

in  the  same  direction,  and 'nearly  in  the  same  plane,  as 
if  thrown  off  from  one  equator;  2d.  The  motions  of  the 
satellites  about  their  primaries  are  mostly  in  the  same 
direction  as  that  of  their  primaries  about  the  sun ;  3d. 
The  rotation  of  most  of  these  bodies  on  their  axes,  and 
also  of  the  sun,  is  in  the  same  direction  as  the  motion 
of  the  planets  about  the  sun ;  4th.  The  orbits  of  the 
planets,  excluding  asteroids,  and  their  satellites,  have  but 
a  comparatively  small  eccentricity ;  5th.  Certain  nebulse 
are  observable  in  the  heavens  which  are  not  yet  con- 
densed into  solids,  but  are  still  bright  gas. 

The  materialistic  evolutionist  takes  up  the  idea  of  a 
universe  of  material  world-stuff  without  form,  and  void, 
but  so  endowed  as  to  develop  itself  into  orderly  worlds, 
and  adds  to  it  this  exceeding  advance,  that  when  soil, 
sun,  and  chemical  laws  found  themselves  properly  re- 
lated, a  force  in  matter,  latent  for  a  million  eons  in  the 
original  cloud,  comes  forward,  and  dead  matter  becomes 
alive  in  the  lowest  order  of  vegetable  life ;  there  takes 
place,  as  Herbert  Spencer  says,  "a  change  from  an  indefi- 
nite, incoherent  homogeneity,  into  a  definite,  coherent 
heterogeneity,  through  continuous  differentiation  and 
integration."  The  dead  becomes  alive ;  matter  passes 
from  unconsciousness  to  consciousness ;  passes  up  from 
plant  to  animal,  from  animal  to  man  ;  takes  on  power  to 
think,  reason,  love,  and  adore.  The  theistic  evolution- 
ist may  think  that  the  same  process  is  gone  through, 
but  that  an  ever-present  and  working  God  superin- 
tends, guides,  and  occasionally  bestows  a  new  endow- 
ment of  power  that  successively  gives  life,  conscious- 
ness, mental,  affectional,  and  spiritual  capacity. 

Is  this  world-theory  true  ?  and  if  so,  is  either  of  the 


THE  NEBULAR  HYPOTHESIS.  185 

evolution  theories  true,  also  ?  If  the  first  evolution 
theory  is  true,  the  evolved  man  will  hardly  know  which 
to  adore  most,  the  Being  that  could  so  endow  matter,  or 
the  matter  capable  of  such  endowment. 

There  are  some  difficulties  in  the  way  of  the  accept- 
ance of  the  nebular  hypothesis  that  compel  many  of 
the  most  thorough  scientists  of  the  day  to  withhold 
their  assent  to  its  entirety.  The  latest,  and  one  of  the 
most  competent  writers  on  the  subject,  Professor  Kew- 
comb,  who  is  a  mathematical  astronomer,  and  not  an 
easy  theorist,  evolving  the  system  of  the  universe  from 
the  depth  of  his  own  consciousness,  says :  "  Should  any 
one  be  sceptical  as  to  the  sufficiency  of  these  laws  to 
account  for  the  present  state  of  things,  science  can 
furnish  no  evidence  strong  enough  to  overthrow  his 
doubts  until  the  sun  shall  be  found  to  be  growing 
smaller  by  actual  measurement,  or  the  nebulae  be  act- 
ually seen  to  condense  into  stars  and  systems."  In 
one  of  the  most  elaborate  defences  of  the  theory,  it  is 
argued  that  the  hypothesis  explains  why  only  one  of 
the  four  planets  nearest  the  sun  can  have  a  moon,  and 
why  there  can  be  no  planet  inside  of  Mercury.  The 
discovery  of  the  two  satellites  to  Mars  and  of  the  planet 
Vulcan  makes  it  all  the  worse  for  these  facts. 

Some  of  the  objections  to  the  theory  should  be 
known  by  every  thinker.  Laplace  must  have  the  cloud 
"  diffused  in  consequence  of  excessive  heat,"  etc.  Helm- 
holtz,  in  order  to  account  for  the  heat  of  the  contract- 
ing sun,  must  have  the  cloud  relatively  cold.  How  he 
and  his  followers  diffused  the  cloud  without  heat  is  not 
stated. 

The  next  difficulty  is   that  of  rotation.     The  laws 


186  THE  NEBULAR  HYPOTHESIS. 

of  science  compel  a  contraction  into  one  non-rotating 
body — a  central  sun,  indeed,  but  no  planets  about  it. 
Laplace  cleverly  evades  the  difficulty  by  not  taking 
from  the  hand  of  the  Creator  diffused  gas,  but  a  sun 
with  an  atmosphere  filling  space  to  the  orbit  of  Nep- 
tune, and  already  in  revolution.  He  says :  "  It  is  four 
millions  to  one  that  all  motions  of  the  planets,  rotations 
and  revolutions,  were  at  once  imparted  by  an  original 
commOn  cause,  of  which  we  know  neither  the  nature 
nor  the  epoch."  Helmholtz  says  of  rotation,  "  the  ex- 
istence of  which  must  be  assumed."  Professor  New- 
comb  says  that  the  planets  would  not  be  arranged  as 
now,  each  one  twice  as  far  from  the  sun  as  the  next 
interior  one,  and  the  outer  ones  made  first,  but  that 
all  would  be  made  into  planets  at  once,  and  the  small 
inner  ones  quite  likely  to  cool  off  more  rapidly. 

It  is  a  very  serious  difficulty  that  at  least  one  satel- 
lite does  not  revolve  in  the  right  direction.  How  Nep- 
tune or  Uranus  could  throw  their  moons  backward  from 
its  equator  is  not  easily  accounted  for.  It  is  at  least 
one  Parthian  arrow  at  the  system,  not  necessarily  fatal, 
but  certainly  dangerous. 

A  greater  difficulty  is  presented  by  the  recently  dis'- 
covered  satellites  of  Mars.  The  inner  one  goes  round 
the  planet  in  one-third  part  of  the  time  of  the  latter's 
revolution.  How  Mars  could  impart  three  times  the 
speed  to  a  body  flying  off  its  surface  that  it  has  itself, 
has  caused  several  defenders  of  the  hypothesis  to  rush 
forward  with  explanations,  but  none  with  anything 
more  than  mere  imaginary  collisions  with  some  comet. 
It  is  to  be  noticed  that  accounting  for  three  times  the 
speed  is  not  enough;  for  as  Mars  shrunk  away  from  the 


THE  NEBULAR  HYPOTHESIS.  187 

ring  that  formed  that  satellite,  it  ought  itself  to  attain 
more  speed,  as  the  sun  revolves  faster  than  its  planets, 
and  the  earth  faster  than  its  moon.  In  defending  the 
hypothesis,  Mitchel  said :  "  Suppose  we  had  discovered 
that  it  required  more  time  for  Saturn  or  Jupiter  to  ro- 
tate on  their  axes  than  for  their  nearest  moon  to  re- 
volve round  them  in  its  orbit ;  this  would  have  falsified 
the  theory."  It  is  also  asserted  that  the  newly  discover- 
ed planet  Vulcan  makes  an  orbital  in  less  time  than  the 
sun  makes  an  axial  revolution. 

In  regard  to  one  Martial  moon,  Professor  Kirkwood, 
on  whom  Proctor  conferred  the  highest  title  that  could 
be  conferred, "  the  modern  Kepler,"  says :  "  Unless  some 
explanation  can  be  given,  the  short  period  of  the  inner 
satellite  will  be  doubtless  regarded  as  a  conclusive  argu- 
ment against  the  nebular  hypothesis,"  If  gravitation 
be  sufficient  to  account  for  the  various  motions  of  the 
heavenly  bodies,  we  have  a  perplexing  problem  in  the 
star  known  as  1830  Goombridge,  now  in  the  Hunting 
Dogs  of  Bootes.  It  is  thought  to  have  a  speed  of  two 
hundred  miles  per  second  —  a  velocity  that  all  the 
known  matter  in  the  universe  could  not  give  to  the  star 
by  all  its  combined  attraction.  Neither  could  all  that 
attraction  stop  the  motion  of  the  star,  or  bend  it  into 
an  orbit.  Its  motion  must  be  accounted  for  on  some 
hypothesis  other  than  the  nebular. 

The  nebulae  which  we  are  able  to  observe  are  not  al- 
together confirmatory  of  the  hypothesis  under  consider- 
ation. They  have  the  most  fantastic  shapes,  as  if  they 
had  no  relation  to  rotating  suns  in  the  formative  stages. 
There  are  vast  gaps  in  the  middle,  where  they  ought 
to  be  densest.  Mr.  Plumer,  in  the  Natural  Science  He- 


188  THE  NEBULAR  HYPOTHESIS. 

view,  says,  in  regard  to  the  results  of  the  spectroscopic 
revelations:  "We  are  furnished  with  distinct  proof  that 
the  gases  so  examined  are  not  only  of  nearly  equal  den- 
sity, but  that  they  exist  in  a  low  state  of  tension.  This 
fact  is  fatal  to  the  nebular  theory" 

In  the  autumn  of  1876  a  star  blazed  out  in  Cygnus, 
which  promised  to  throw  a  flood  of  light  on  the  ques- 
tion of  world-making.  Its  spectrum  was  like  some  of 
the  fixed  stars.  It  probably  blazed  out  by  condensation 
from  some  previously  invisible  nebula.  But  its  brill- 
iancy diminished  swiftly,  when  it  ought  to  have  taken 
millions  of  years  to  cool.  If  the  theory  was  true,  it 
ought  to  have  behaved  very  differently.  It  should 
have  regularly  condensed  from  gas  to  a  solid  sun  by 
slow  process.  But,  worst  of  all,  after  being  a  star  awhile, 
it  showed  unmistakable  proofs  of  turning  into  a  cloud- 
mist — a  star  into  a  nebula,  instead  of  vice  versa.  A  pos- 
sible explanation  will  be  considered  under  variable  stars. 

Such  are  a  few  of  the  many  difficulties  in  the  way  of 
accepting  the  nebular  hypothesis,  as  at  present  explain- 
ed, as  being  the  true  mode  of  development  of  the  solar 
system.  Doubtless  it  has  come  from  a  hot  and  diffused 
condition  into  its  present  state ;  but  when  such  men  as 
Proctor,  l^ewcomb,  and  Kirkwood  see  difficulties  that 
cannot  be  explained,  contradictions  that  cannot  be  rec- 
onciled by  the  principles  of  this  theory,  surely  lesser 
men  are  obliged  to  suspend  judgment,  and  render  the 
Scotch  verdict  of  "not  proven."  Whatever  truth  there 
may  be  in  the  theory  will  survive,  and  be  incorporated 
into  the  final  solution  of  the  problem  ;  which  solution 
will  be  a  much  grander  generalization  of  the  human 
mind  than  the  nebular  hypothesis. 


THE  NEBULAR  HYPOTHESIS.  189 

Of  some  things  we  feel  very  sure :  that  matter  was 
once  without  form  and  void,  and  darkness  rested  on  the 
face  of  the  mighty  deeps;  that, instead  of  chaos,  we  have 
now  cosmos  and  beauty ;  and  that  there  is  some  process 
by  which  matter  has  been  brought  from  one  state  to 
the  other.  Whether,  however,  the  nebular  hypothesis 
lays  down  the  road  travelled  to  this  transfiguration,  we 
are  not  sure.  Some  of  it  seems  like  solid  rock,  and 
some  like  shifting  quicksand.  Doubtless  there  is  a 
road  from  that  chaos  to  this  fair  cosmos.  The  nebular 
hypothesis  has  surveyed,  worked,  and  perfected  many 
long  reaches  of  this  road,  but  the  rivers  are  not  bridged, 
the  chasms  not  filled,  nor  the  mountains  tunnelled. 

When  men  attempt  to  roll  the  hypothesis  of  evolu- 
tion along  the  road  of  the  nebular  hypothesis  of  worlds, 
and  even  beyond  to  the  production  .of  vegetable  and 
animal  life,  mind  and  affection,  the  gaps  in  the  road 
become  evident,  and  disastrous. 

A  soul  that  has  reached  an  adoration  for  the  Supreme 
Father  cares  not  how  he  has  made  him.  Doubtless  the 
way  God  chose  was  the  best.  It  is  as  agreeable  to  have 
beeji  thought  of  and  provided  for  in  the  beginning,  to 
have  had  a  myriad  ages  of  care,  and  to  have  come  from 
the  highest  existent  life  at  last,  as  to  have  been  made  at 
once,  by  a  single  act,  out  of  dust.  The  one  who  is  made 
is  not  to  say  to  the  Maker,  "Why  hast  thou  formed  me 
in  this  or  that  manner  ?"  We  only  wish  the  question 
answered  in  what  manner  we  were  really  made. 

Evolution,  without  constant  superintendence  and  oc- 
casional new  inspiration  of  power,  finds  some  tremen- 
dous chasms  in  the  road  it  travels.  These  must  be  span- 
ned by  the  power  of  a  present  God  or  the  airy  imagiua- 


190  THE  NEBULAR  HYPOTHESIS. 

tion  of  man.  Dr.  McCosli  has  happily  enumerated  some 
of  these  tremendous  gaps  over  which  mere  force  cannot 
go.  Given,  then,  matter  with  mechanical  power  only, 
what  are  the  gaps  between  it  and  spirituality  \ 

"  1.  Chemical  action  cannot  be  produced  by  mechan- 
ical power. 

"  2.  Life,  even  in  the  lowest  forms,  cannot  be  pro- 
duced from  unorganized  matter. 

"  3.  Protoplasm  can  be  produced  only  by  living  mat- 
ter. 

"  4.  Organized  matter  is  made  up  of  cells,  and  can  be 
produced  only  by  cells.  Whence  the  first  cell  ? 

"  5.  A  living  being  can  be  produced  only  from  a  seed 
or  germ.  "Whence  the  first  vegetable  seed  ? 

"6.  An  animal  cannot  be  produced  from  a  plant. 
Whence  the  first  animal  ? 

"  7.  Sensation  cannot  be  produced  in  insentient  matter. 

"8.  The  genesis  of  a  new  species  of  plant  or  animal 
has  never  come  under  the  cognizance  of  man,  either  in 
pre-human  or  post-human  ages,  either  in  pre-scientific 
or  scientific  times.  Darwin  acknowledges  this,  and  says 
that,  should  a  new  species  suddenly  arise,  we  have  no 
means  of  knowing  that  it  is  such. 

"  9.  Consciousness — that  is,  a  knowledge  of  self  and 
its  operations — cannot  be  produced  out  of  mere  matter 
or  sensation. 

"  10.  We  have  no  knowledge  of  man  being  generated 
out  of  the  lower  animals. 

"  11.  All  human  beings,  even  savages,  are  capable  of 
forming  certain  high  ideas,  such  as  those  of  God  and 
duty.  The  brute  creatures  cannot  be  made  to  enter- 
tain these  by  any  training. 


THE  NEBULAR  HYPOTHESIS.  191 

"  With  such  tremendous  gaps  in  the  process,  the  the- 
ory which  would  derive  all  things  out  of  matter  by  de- 
velopment is  seen  to  be  a  very  precarious  one." 

The  truth,  according  to  the  best  judgment  to  be 
formed  in  the  present  state  of  knowledge,  would  seem 
to  be  about  this :  The  nebular  hypothesis  is  correct  in 
all  the  main  facts  on  which  it  is  based ;  but  that  neither 
the  present  forces  of  matter,  nor  any  other  forces  con- 
ceivable to  the  mind  of  man,  with  which  it  can  possibly 
be  endowed,  can  account  for  all  the  facts  already  ob- 
served. There  is  a  demand  for  a  personal  volition,  for 
an  exercise  of  intelligence,  for  the  following  of  a  divine 
plan  that  embraces  a  final  perfection  through  various 
and  changeful  processes.  The  five  great  classes  of  facts 
that  sustain  the  nebular  hypothesis  seem  set  before  us 
to  show  the  regular  order  of  working.  The  several 
facts  that  will  not,  so  far  as  at  present  known,  accord 
with  that  plan,  seem  to  be  set  before  us  to  declare  the 
presence  of  a  divine  will  and  power  working  his  good 
pleasure  according  to  the  exigencies  of  time  and  place. 


X. 

THE   STELLAR  SYSTEM. 

"  The  heavens  number  out  the  glory  of  the  strong  God."— DAVID. 

9 


Richter  says  that  "  an  angel  once  took  a  man  and  stripped  him  of  his 
flesh,  and  lifted  him  up  into  space  to  show  him  the  glory  of  the  universe. 
When  the  flesh  was  taken  away  the  man  ceased  to  be  cowardly,  and  was 
ready  to  fly  with  the  angel  past  galaxy  after  galaxy,  and  infinity  after  in- 
finity, and  so  man  and  angel  passed  on,  viewing  the  universe,  until  the 
sun  was  out  of  sight — until  our  solar  system  appeared  as  a  speck  of  light 
against  the  black  empyrean,  and  there  was  only  darkness.  And  they 
looked  onward,  and  in  the  infinities  of  light  before,  a  speck  of  light  ap- 
peared, and  suddenly  they  were  in  the  midst  of  rushing  worlds.  But  they 
passed  beyond  that  system,  and  beyond  system  after  system,  and  infinity 
after  infinity,  until  the  human  heart  sank,  and  the  man  cried  out:  'End 
is  there  none  of  the  universe  of  God  ?'  The  angel  strengthened  the  man 
by  words  of  counsel  and  courage,  and  they  flew  on  again  until  worlds  left 
behind  them  were  out  of  sight,  and  specks  of  light  in  advance  were  trans- 
formed, as  they  approached  them,  into  rushing  systems ;  they  moved  over 
architraves  of  eternities,  over  pillars  of  immensities,  over  architecture  of 
galaxies,  unspeakable  in  dimensions  and  duration,  and  the  human  heart 
sank  again  and  called  out :  '  End  is  there  none  of  the  universe  of  God  ?' 
And  all  the  stars  echoed  the  question  with  amazement:  'End  is  there 
none  of  the  universe  of  God  ?'  And  this  echo  found  no  answer.  They 
moved  on  again  past  immensities  of  immensities,  and  eternities  of  eterni- 
ties, until  in  the  dizziness  of  uncounted  galaxies  the  human  heart  sank  for 
the  last  time,  and  called  out :  '  End  is  there  none  of  the  universe  of  God  ?' 
And  again  all  the  stars  repeated  the  question,  and  the  angel  answered : 
'  End  is  there  none  of  the  universe  of  God.  Lo,  also,  there  is  no  be- 
ginning.'" 


THE  OPEN  PAGE  OF  THE  HEAVENS.  195 


X. 

THE  OPEN  PAGE  OF  THE  HEAVENS. 

THE  Greeks  set  their  mythological  deities  in  the  skies, 
and  read  the  revolving  pictures  as  a  starry  poem.  Not 
that  they  were  the  first  to  set  the  blazonry  of  the  stars 
as  monuments  of  their  thought ;  we  read  certain  allu- 
sions to  stars  and  asterisms  as  far  back  as  the  time  of 
Job.  And  the  Pleiades,  Arcturus,  and  Orion  are  some 
of  the  names  used  by  Him  who  "  calleth  all  the  stars  by 
their  names,  in  the  greatness  of  his  power."  Homer  and 
Hesiod,  750  B.C.,  allude  to  a  few  stars  and  groups.  The 
Arabians  very  early  speak  of  the  Great  Bear ;  but  the 
Greeks  completely  nationalized  the  heavens.  They  col- 
onized the  earth  widely,  but  the  heavens  completely ; 
and  nightly  over  them  marched  the  grand  procession  of 
their  apotheosized  divinities.  There  Hercules  perpetu- 
ally wrought  his  mighty  labors  for  the  good  of  man ; 
there  flashed  and  faded  the  changeful  star  Algol,  as  an 
eye  in  the  head  of  the  snaky-haired  Medusa;  over  them 
flew  Pegasus,  the  winged  horse  of  the  poet,  careering 
among  the  stars ;  there  the  ship  Argo,  which  had  ex- 
plored all  strange  seas  of  earth,  nightly  sailed  in  the  in- 
finite realms  of  heaven;  there  Perseus  perpetually  killed 
the  sea-monster  by  celestial  aid,  and  perpetually  won  the 
chained  Andromeda  for  his  bride.  Very  evident  was 
their  recognition  of  divine  help :  equally  evident  was 


106  THE  STELLAR  SYSTEM. 

their  assertion  of  human  ability  and  dominion.  They 
gathered  the  illimitable  stars,  and  put  uncountable  suns 
into  the  shape  of  the  Great  Bear  —  the  most  colossal 
form  of  animal  ferocity  and  strength  —  across  whose 
broad  forehead  imagination  grows  weary  in  flying ;  but 
they  did  not  fail  to  put  behind  him  a  representative  of 
themselves,  who  forever  drives  him  around  a  sky  that 
never  sets — a  perpetual  type  that  man's  ambition  and 
expectation  correspond  to  that  which  has  always  been 
revealed  as  the  divine. 

The  heavens  signify  much  higher  power  and  wisdom 
to  us;  we  retain  the  old  pictures  and  groupings  for  the 
convenience  of  finding  individual  stars.  It  is  enough 
for  the  astronomer  that  we  speak  of  a  star  as,  right 
ascension,  Ih.  13m.  45s.,  declination,  88°  40'.  But  for 
most  people,  if  not  all,  it  is  better  to  call  it  Polaris.  So 
we  might  speak  of  a  lake  in  latitude  42°  40',  longitude 
79°  22',  but  it  would  be  clearer  to  most  persons  to  say 
Chautaiiqna.  For  exact  location  of  a  star,  right  ascension 
and  declination  must  be  given;  but  for  general  indica- 
tion its  name  or  place  in  a  constellation  is  sufficiently 
exact.  The  heaven  is  rather  indeterminably  laid  out 
in  irregular  tracts,  and  the  mythological  names  are  pre- 
served. The  brightest  stars  are  then  indicated  in  order 
by  the  letters  of  the  Greek  alphabet — Alpha  (a),  Beta 
(j3),  Gamma  (y),  etc.  Stars  are  numbered  in  the  order 
of  right  ascension  without  regard  to  their  brilliancy. 
Thus  No.  50  Cygni  is  Alpha ;  K.  A.,  20h.  36m.l9s.  No.  61 
is,  R.  A.,  21.h.  Om.  10s.  Thus  any  star  unknown  by  name 
is  easily  found.  An  acquaintance  with  the  names,  pecu- 
liarities, and  movements  of  the  stars  visible  at  different 
seasons  of  the  year  is  an  unceasing  source  of  pleasure.  It 


THE  OPEN  PAGE  OF  THE  HEAVENS.  197 

* 

is  not  vision  alone  that  is  gratified,  for  one  fine  enough 
may  hear  the  morning  stars  sing  together,  and  understand 
the  speech  that  day  nttereth  unto  day,  and  the  knowl- 
edge that  night  showeth  unto  night.  One  never  can  be 
alone  if  he  is  familiarly  acquainted  with  the  stars.  He 
rises  early  in  the  summer  morning,  that  he  may  see  his 
winter  friends ;  in  winter,  that  he  may  gladden  himself 
with  a  sight  of  the  summer  stars.  He  hails  their  suc- 
cessive rising  as  he  does  the  coming  of  his  personal 
friends  from  beyond  the  sea.  On  the  wide  ocean  he  is 
commercing  with  the  skies,  his  rapt  soul  sitting  in  his 
eyes.  Under  the  clear  skies  of  the  East  he  hears  God's 
voice  speaking  to  him,  as  to  Abraham,  and  saying, 
"  Look  now  toward  the  heavens,  and  tell  the  number  of 
the  stars,  if  thou  be  able  to  number  them." 

A  general  acquaintance  with  the  stars  will  be  first  at- 
tempted ;  a  more  particular  knowledge  afterward.  Fig. 
67  (page  201)  is  a  map  of  the  circumpolar  region,  which 
is  in  full  view  every  clear  night.  It  revolves  daily 
round  Polaris,  its  central  point.  Toward  this  star,  the 
two  end  stars  of  the  Great  Dipper  ever  point,  and  are 
in  consequence  called  "the  Pointers."  The  map  may 
be  held  toward  the  northern  sky  in  such  a  position  as 
the  stars  may  happen  to  be.  The  Great  Bear,  or  Dipper, 
will  be  seen  at  nine  o'clock  in.  the  evening  above  the 
pole  in  April  and  May ;  west  of  the  pole,  the  Pointers 
downward,  in  July  and  August ;  close  to  the  north  ho- 
rizon in  October  and  November;  and  east  of  the  pole  the 
Pointers  highest,  in  January  and  February.  The  names 
of  such  constantly  visible  stars  should  be  familiar.  In 
order,  from  the  end  of  the  tail  of  the  Great  Bear,  we 
have  Benetnasch  rj,  Mizar  £,  Little  Alcor  close  to  it,  Ali- 


198  THE  STELLAR  SYSTEM. 

oth  t,  Megrez  §,  at  the  junction,  has  been  growing  dim- 
mer for  a  century,  Phad  y,  Dubhe  and  Merak.  It  is 
best  to  get  some  facility  at  estimating  distances  in  de- 
grees. Dubhe  and  Merak,  "  the  Pointers,"  are  five  de- 
grees apart.  Eighteen  degrees  forward  of  Dubhe  is 
the  Bear's  nose  ;  and  three  pairs  of  stars,  fifteen  degrees 
apart,  show  the  position  of  the  Bear's  three  feet.  Fol- 
low "the  Pointers"  twenty-nine  degrees  from  Dubhe, 
and  we  come  to  the  pole-star.  This  star  is  double,  made 
of  two  suns,  both  appearing  as  one  to  the  naked  eye. 
It  is  a  test  of  an  excellent  three-inch  telescope  to  resolve 
it  into  two.  Three  stars  beside  it  make  the  curved-up 
handle  of  the  Little  Dipper  of  Ursa  Minor.  Between 
the  two  Bears,  thirteen  degrees  from  Megrez,  and  eleven 
degrees  from  Mizar,  are  two  stars  in  the  tail  of  the 
Dragon,  which  curves  about  to  appropriate  all  the  stars 
not  otherwise  assigned.  Follow  a  curve  of  fifteen  stars, 
doubling  back  to  a  quadrangle  from  five  to  three  de- 
grees on  a  side,  and  thirty-five  degrees  from  the  pole,  for 
his  head.  His  tongue  runs  out  to  a  star  four  degrees 
in  front.  We  shall  find,  hereafter,  that  the  foot  of  Her- 
cules stands  on  this  head.  This  is  the  Dragon  slain  by 
Cadmus,  and  whose  teeth  produced  such  a  crop  of  san- 
guinary men. 

The  star  Thuban  was  once  the  pole-star.  In  the 
year  B.C.  2300  it  was  ten  times  nearer  the  pole  than 
Polaris  is  now.  In  the  year  A.D.  2100  the  pole  will 
be  within  30'  of  Polaris ;  in  A.D.  7500,  it  will  be  at 
a  of  Cepheus ;  in  A.D.  13,500,  within  7°  of  Yega ;  in 
A.D.  15,700,  at  the  star  in  the  tongue  of  Draco ;  in 
A.D.  23,000,  at  Thuban  ;  in  A.D.  28,000,  back  to  Polaris. 
This  indicates  no  change  in  the  position  of  the  dome 


THE  OPEN  PAGE  OF  THE  HEAVENS.  199 

of  stars,  but  a  change  in  the  direction  of  the  axis  of 
the  earth  pointing  to  these  various  places  as  the  cy- 
cles pass.  As  the  earth  goes  round  its  orbit,  the  axis, 
maintaining  nearly  the  same  direction,  really  points  to 
every  part  of  a  circle  near  the  north  star  as  large  as  the 
earth's  orbit,  that  is,  185,000,000  miles  in  diameter.  But, 
as  already  shown,  that  circle  is  too  small  to  be  discerni- 
ble at  our  distance.  The  wide  circle  of  the  pole  through 
the  ages  is  really  made  up  of  the  interlaced  curves  of 
the  annual  curves  continued  through  25,870  years. 
The  stein  of  the  spinning  top  wavers,  describes  a  circle, 
and  finally  falls  ;  the  axis  of  the  spinning  earth  wavers, 
describes  a  circle  of  nearly  26,000  years,  and  never 
falls. 

The  star  y  Draconis,  also  called  Etanin,  is  famous  in 
modern  astronomy,  because  observations  on  this  star 
led  to  the  discovery  of  the  aberration  of  light.  If  we 
held  a  glass  tube  perpendicularly  out  of  the  window  of 
a  car  at  rest,  when  the  rain  was  falling  straight  down, 
we  could  see  the  drops  pass  directly  through.  Put 
the  car  in  motion,  and  the  'drops  would  seem  to  start 
toward  us,  and  the  top  of  the  tube  must  be  bent  forward, 
or  the  drops  entering  would  strike  on  the  backside  of 
the  tube  carried  toward  them.  So  our  telescopes  are 
bent  forward  on  the  moving  earth,  to  enable  the  entered 
light  to  reach  the  eye-piece.  Hence  the  star  does  not 
appear  just  where  it  is.  As  the  earth  moves  faster  in 
some  parts  of  its  orbit  than  others,  this  aberration  is 
sometimes  greater  than  at  others.  It  is  fortunate  that 
light  moves  with  a  uniform  velocity,  or  this  difficult 
problem  would  be  still  further  complicated.  The  dis- 
placement of  a  star  from  this  course  is  about  20".  43. 


200  THE  STELLAR  SYSTEM. 

On  the  side  of  Polaris,  opposite  to  Ursa  Major,  is 
King  Cephens,  made  of  a  few  dim  stars  in  the  form  of 
the  letter  K.  Near  by  is  his  brilliant  wife  Cassiopeia, 
sitting  on  her  throne  of  state.  They  were  the  grace- 
less parents  who  chained  their  daughter  to  a  rock  for 
the  sea-monster  to  devour ;  but  Perseus,  swift  with  the 
winged  sandals  of  Mercury,  terrible  with  his  avenging 
sword,  and  invincible  with  the  severed  head  of  Me- 
dusa, whose  horrid  aspect  of  snaky  hair  and  scaly  body 
turned  to  stone  every  beholder,  rescues  the  maiden  from 
chains,  and  leads  her  away  by  the  bands  of  love.  Noth- 
ing could  be  more  poetical  than  the  life  of  Perseus. 
When  he  went  to  destroy  the  dreadful  Gorgon,  Medusa, 
Pluto  lent  him  his  helmet,  which  would  make  him  in- 
visible at  will ;  Minerva  loaned  her  buckler,  impenetra- 
ble, and  polished  like  a  mirror;  Mercury  gave  him 
a  dagger  of  diamonds,  and  his  winged  sandals,  which 
would  carry  him  through  the  air.  Coming  to  the 
loathsome  thing,  he  would  not  look  upon  her,  lest  he, 
too,  be  turned  to  stone ;  but,  guided  by  the  reflection 
in  the  buckler,  smote  off  her  head,  carried  it  high  over 
Libya,  the  dropping  blood  turning  to  serpents,  which 
have  infested  those  deserts  ever  since. 

The  human  mind  has  always  been  ready  to  deify 
and  throne  in  the  skies  the  heroes  that  labor  for  others. 
Both  Perseus  and  Hercules  are  divine  by  one  parent, 
and  human  by  the  other.  They  go  up  and  down  the 
earth,  giving  deliverance  to  captives,  and  breaking  ev- 
ery yoke.  They  also  seek  to  purge  away  all  evil ;  they 
slay  dragons,  gorgons,  devouring  monsters,  cleanse  the 
foul  places  of  earth,  and  one  of  them  so  wrestles  with 
death  as  to  win  a  victim  from  his  grasp.  Finally,  by 


CIRCUMPOLAR  CONSTELLATIONS.  201 


Fig.  67. — Circnmpolar  Constellations.  Always  visible.  In  this  position. — Janu- 
ary 20th,  at  10  o'clock ;  February  4th,  at  9  o'clock ;  and  February  19th,  at  8 
o'clock. 

an  ascension  in  light,  they  go  up  to  be  in  light  forever. 
They  are  not  ideally  perfect.  They  right  wrong  by 
slaying  wrong -doers,  rather  than  by  being  crucified 
themselves;  they  are  just  murderers;  but  that  only 
plucks  the  fruit  from  the  tree  of  evil.  They  never 
attempted  to  infuse  a  holy  life.  They  punished  rather 
than  regenerated.  It  must  be  confessed,  also,  that  they 
were  not  sinless.  But  they  were  the  best  saviors  the 
race  could  imagine,  and  are  examples  of  that  perpetual 
effort  of  the  human  mind  to  incarnate  a  Divine  Helper 
who  shall  labor  and  die  for  the  good  of  men. 


202 


THE  STELLAR  SYSTEM. 


Fig.  68 Algol  is  on  the  Meridian,  51°  South  of  Pole.— At  10  o'clock,  December 

7th  ;  9  o'clock,  December  22d ;  8  o'clock,  January  5th. 

Equatorial  Constellations. 

If  we  turn  our  backs  on  Polaris  on  the  10th  of  No- 
vember, at  10  o'clock  in  the  evening,  and  look  directly 
overhead,  we  shall  see  the  beautiful  constellation  of 
Andromeda.  Together  with  the  square  of  Pegasus,  it 
makes  another  enormous  dipper.  The  star  a  Alpheratz 
is  in  her  face,  the  three  at  the  left  cross  her  breast. 
|3  and  the  two  above  mark  the  girdle  of  her  loins,  and 
•y  is  in  the  foot.  Perseus  is  near  enough  for  help ; 
and  Cetus,  the  sea-monster,  is  far  enough  away  to  do 
no  harm.  Below,  and  east  of  Andromeda,  is  the  Ram 
of  the  golden  fleece,  recognizable  by  the  three  stars  in 
an  acute  triangle.  The  brightest  is  called  Arietis,  or 
Hamel.  East  of  this  are  the  Pleiades,  and  the  Y-shaped 
Hyades  in  Taurus,  or  the  Bull.  The  Pleiades  rise  about 
9  o'clock  on  the  evening  of  the  10th  of  September,  and 
at  3  o'clock  A.M.  on  June  10th. 


EQUATORIAL   CONSTELLATIONS. 


203 


Fig.  69.— Capella  (45°  from  the  Pole)  and  Rigel  (100°)  are  on  the  Meridian  at 
8  o'clock  February  7th,  9  o'clock  January  22d,  and  at  10  o'clock  January  7th. 

Fig.  69  extends  east  and  south  of  our  last  map.  It 
is  the  most  gorgeous  section  of  our  heavens.  (See  the 
Notes  to  the  Frontispiece.)  Note  the  triangle,  26°  on 
a  side,  made  by  Betelguese,  Sirius,  and  Procyon.  A 
line  from  Procyon  to  Pollux  leads  quite  near  to  Polaris. 
Orion  is  the  mighty  hunter.  Under  his  feet  is  a  hare, 
behind  him  are  two  dogs,  and  before  him  is  the  rushing 
bull.  The  curve  of  stars  to  the  right  of  Bellatrix,  7, 
represents  his  shield  of  the  Nemean  lion's  hide.  The 
three  stars  of  his  belt  make  a  measure  3°  long ;  the 
upper  one,  Mintaka,  is  less  than  30'  south  of  the  equi- 
noctial. The  ecliptic  passes  between  Aldebaran  and  the 
Pleiades.  Sirius  rises  about  9  o'clock  P.M.  on  the  1st  of 
December,  and  about  4  o'clock  A.M.  on  the  16th  of  Au- 
gust. Procyon  rises  about  half  an  hour  earlier. 


204 


THE  STELLAR  SYSTEM. 


Fig.  70  — Regains  comes  cm  the  Meridian,  79°  south  from  the  Pole,  at  10  o'clock 
March  23d,  9  o'clock  April  8th,  and  at  S  o'clock  April  23d. 

Fig.  TO  continues  eastward.  Note  the  sickle  in  the 
head  and  neck  of  the  Lion.  The  star  /3  is  Denebola,  in 
his  tail.  Arcturus  appears  by  the  word  Bootes,  at  the 
edge  of  the  map.  These  two  stars  make  a  triangle  with 
Spica,  about  35°  on  a  side.  The  geometric  head  of 
Hydra  is  easily  discernible  east  of  Procyon.  The  star 
y  in  the  Virgin  is  double,  with  a  period  of  145  years. 
£  is  just  above  the  equinoctial.  There  is  a  fine  nebula 
two-thirds  of  the  way  from  §  to  )j,  and  a  little  above  the 
line  connecting  the  two.  Coma  Berenices  is  a  beauti- 
ful cluster  of  faint  stars.  Spica  rises  at  9  o'clock  on 
the  10th  of  February,  at  5  o'clock  A.M.  on  the  6th  of 
November. 


EQUATORIAL   CONSTELLATIONS.  205 


Fig.  71.— Arctnrns  comes  to  the  Meridian,  70°  from  the  Pole,  at  10  o'clock  May 
25th,  9  o'clock  Juue  9th,  aud  at  8  o'clock  Jane  25th. 

Fig.  71  represents  the  sky  to  the  eastward  and  north- 
ward of  the  last.  A  line  drawn  from  Polaris  and 
Benetnasch  conies  east  of  Arcturus  to  the  little  triangle 
called  his  sons.  Bootes  drives  the  Great  Bear  round 
the  pole.  Arcturus  arid  Denebola  make  a  triangle  with 
a,  also  called  Cor  Creroli,  in  the  Hunting  Dogs.  This 
triangle,  and  the  one  having  the  same  base,  with  Spica 
for  its  apex,  is  called  the  "Diamond  of  the  Virgin." 
Hercules  appears  head  down — a  in  the  face,  |3, 7,  £  in  his 
shoulders,  TT  and  »j  in  the  loins,  r  in  the  knee,  the  foot 
being  bent  to  the  stars  at  the  right.  The  Serpent's 
head,  making  an  x ,  is  just  at  the  right  of  the  7  of 
Hercules,  and  the  partial  circle  of  the  Northern  Crown 
above.  The  head  of  Draco  is  seen  at  ]3  on  the  left  of 
the  map.  Arcturus  rises  at  9  o'clock  about  the  20th  of 
February,  and  at  5  A.M.  on  the  22d  of  October ;  Kegu- 
lus  3h.  35m.  earlier. 


206 


THE  STELLAR  SYSTEM. 


Fig.  72.— Altair  conies  to  the  Meridian,  82°  from  the  Pole,  at  10  o'clock  P.M.  Au- 
gust 18th,  at  9  o'clock  September  2d,  and  at  8  o'clock. September  18th. 

Fig.  72  portrays  the  stars  eastward  and  southward. 
Scorpio  is  one  of  the  most  brilliant  and  easily  traced 
constellations.  Antares,  a,  in  the  heart,  is  double.  In 
Sagittarius  is  the  Little  Milk-dipper,  and  west  of  it  the 
bended  bow.  Yega  is  at  the  top  of  the  map.  Near  it 
observe  £,  a  double,  and  c,  a  quadruple  star.  The  point 
to  which  the  solar  system  is  tending  is  marked  by  the 
sign  of  the  earth  below  TT  Herculis.  The  Serpent,  west 
of  Hercules,  and  coiled  round  nearly  to  Aquila,  is  very 
traceable.  In  the  right-hand  lower  corner  is  the  Cen- 
taur. Below,  and  always  out  of  our  sight,  is  the  famous 
a  Centauri.  The  diamond  form  of  the  Dolphin  is  some- 
times called  "  Job's  Coffin."  The  ecliptic  passes  close 


EQUATORIAL   CONSTELLATIONS.  207 


Fi£.  73.  —  Fomalhaut  conies   to  the  Meridian,  only  17°   from   the  horizon,  at 
8  o'clock  November  4th. 

to  ]3  of  Scorpio,  which  star  is  in  the  head.  Antares,  in 
Scorpio,  rises  at  9  o'clock  P.M.  on  May  9th,  and  at  5 
o'clock  A.M.  on  January  5th. 

In  Fig.  73  we  recognize  the  familiar  stars  of  Pegasus, 
which  tell  us  we  have  gone  quite  round  the  heavens. 
Note  the  beautiful  cross  in  the  Swan.  |3  in  the  bill  is 
named  Albireo,  and  is  a  beautiful  double  to  almost  any 
glass.  Its  yellow  and  blue  colors  are  very  distinct. 
The  place  of  the  famous  double  star  61  Cygni  is  seen. 
The  first  magnitude  star  in  the  lower  left-hand  corner  is 
Fomalhaut,  in  the  Southern  Fish,  a  Pegasi  is  in  the 
diagonal  corner  from  Alpheratz,  in  Andromeda.  The 
star  below  Altair  is  ]3  Aquilse,  and  is  called  Alschain  ; 
the  one  above  is  y  Aquilae,  named  Tarazed.  Tin's  is 
not  a  brilliant  section  of  the  sky.  Altair  rises  at  9 
o'clock  on  the  29th  of  May,  and  at  6  o'clock  A.M.  on 
the  11  th  of  January. 


208  THE  STELLAR  SYSTEM. 


Fig.  74. — Southern  Circumpolar  Constellations  invisible  north  of  the  Equator. 

Fig.  74  gives  the  stars  that  are  best  seen  by  per- 
sons south  of  the  earth's  equator.  In  the  ship  is  brill- 
iant Canopus,  and  the  remarkable  variable  rj.  Below  it 
is"  the  beautiful  Southern  Cross,  near  the  pole  of  the 
southern  heavens.  Just  below  are  the  two  first  mag- 
nitude stars  Bungula,  a,  and  Achernar,  /3,  of  the  Centaur. 
Such  a  number  of  unusually  brilliant  stars  give  the 
southern  sky  an  unequalled  splendor.  In  the  midst  of 
them,  as  if  for  contrast,  is  the  dark  hole,  called  by  the 
sailors  the  "  Coal  -  sack,"  where  even  the  telescope  re- 
veals no  sign  of  light.  Here,  also,  are  the  two  Magel- 
lanic  clouds,  both  easily  discernible  by  the  naked  eye ; 
the  larger  two  hundred  times  the  apparent  size  of  the 
moon,  lying  between  the  pole  and  Canopus,  and  the 
other  between  Achernar  and  the  pole.  The  smaller 
cloud  is  only  one-fourth  the  size  of  the  other.  Both  are 
mostly  resolvable  into  groups  of  stars  from  the  fifth  to 
the  fifteenth  magnitude. 


CHARACTERISTICS  OF  THE  STARS.  209 

For  easy  ont-door  finding  of  the  stars  above  the  hori- 
zon at  any  time,  see  star-maps  at  end  of  the  book. 

Characteristics  of  the  Stars. 

Such  a  superficial  examination  of  stars  as  we  have 
made  scarcely  touches  the  subject.  It  is  as  the  study 
of  the  baptismal  register,  where  the  names  were  an- 
ciently recorded,  without  any  knowledge  of  individuals. 
The  heavens  signify  much  more  to  us  than  to  the 
Greeks.  We  revolve  under  a  dome  that  investigation 
has  infinitely  enlarged  from  their  estimate.  Their  lit- 
tle lights  were  turned  by  clumsy  machinery,  held  to- 
gether by  material  connections.  Our  vast  worlds  are 
connected  by  a  force  so  fine  that  it  seems  to  pass  out 
of  the  realm  of  the  material  into  that  of  the  spiritual. 
Animal  ferocity  or  a  human  Hercules  could  image  their 
idea  of  power.  Ours  finds  no  symbol,  but  rises  to  the 
Almighty.  Their  heavens  were  full  of  fighting  Orions, 
wild  bulls,  chained  Andromedas,  and  devouring  mon- 
sters. Our  heavens  are  significant  of  harmony  and 
unity;  all  worlds  carried  by  one  force,  and  all  harmo- 
nized into  perfect  music.  All  their  voices  blend  their 
various  significations  into  a  personal  speaking,  which 
says,  "  Hast  thou  not  heard  that  the  everlasting  God, 
the  Lord,  the  creator  of  the  ends  of  the  earth,  fainteth 
not,  neither  is  weary  ?"  There  is  no  searching  of  his 
understanding.  Lift  up  your  eyes  on  high,  and  behold 
who  hath  created  all  these  things,  that  brought  out  their 
host  by  number,  that  calleth  them  all  by  their  names 
in  the  greatness  of  his  power;  for  that  he  is  strong  in 
power  not  one  faileth. 


210  THE  STELLAR  SYSTEM. 

Number. 

We  find  about  five  thousand  stars  visible  to  the 
naked  eye  in  the  whole  heavens,  both  north  and  south. 
Of  these  twenty  are  of  the  first  magnitude,  sixty-five 
of  the  second,  two  hundred  of  the  third,  four  hundred 
of  the  fourth,  eleven  hundred  of  the  fifth,  and  three 
thousand  two  hundred  of  the  sixth.  We  think  we  can 
easily  number  the  stars;  but  train  a  six-inch  telescope 
on  a  little  section  of  the  Twins,  where  six  faint  stars  are 
visible,  and  over  three  thousand  luminous  points  appear. 
The  seventh  magnitude  has  13,000  stars;  the  eighth, 
40,000 ;  the  ninth,  142,000.  There  are  18,000,000  stars 
in  the  zone  called  the  Milky  Way.  When  our  eyes  are 
not  sensitive  enough  to  be  affected  by  the  light  of  far- 
off  stars  the  tasi meter  feels  their  heat,  and  tells  us  the 
word  of  their  Maker  is  true — "they  are  innumerable."* 

Double  and  Multiple  Stars. 

If  we  look  up  during  the  summer  months  nearly  over- 
head at  the  star  c  Lyrae,  east  of  Vega  (Fig.  72),  we  shall 
see  with  the  naked  eye  that  the  star  appears  a  little 

*  Telescopic  Work. — Look  at  the  Hyndes  and  Pleiades  in  Taurus. 
Notice  the  different  colors  of  stars  in  them  both.  Find  the  cluster 
Pra3sepe  in  Fig.  70,  just  a  trifle  above  a  point  midway  between  Procyon 
and  Regulus.  It  is  equally  distant  from  Procyon  and  a  point  a  little 
below  Pollux.  Sweep  along  the  Milky  Way  almost  anywhere,  and  ob- 
serve the  distribution  of  stars  ;  in  some  places  perfect  crowds,  in  oth- 
ers more  sparsely  scattered.  Find  with  the  naked  eye  the  rich  cluster 
in  Perseus.  Draw  a  line  from  Algol  to  a  of  Perseus  (Fig.  67) ;  turn 
at  right  angles  to  the  right,  at  a  distance  of  once  and  four-tenths  the 
first  line  a  brightness  will  be  seen.  The  telescope  reveals  a  gorgeous 
cluster. 


DOUBLE  AND  MULTIPLE  STARS.  211 

elongated.  Turn  your  opera- glass  upon  it,  and  two 
stars  appear.  Turn  a  larger  telescope  on  this  double 
star,  and  each  of  the  components  separate  into  two.  It 
is  a  double  double  star.  We  know  that  if  two  stars  are 
near  in  reality,  and  not  simply  apparently  so  by  being 
in  the  same  line  of  sight,  they  must  revolve  around  a 
common  centre  of  gravity,  or  rush  to  a  common  ruin. 
Eagerly  we  watch  to  see  if  they  revolve.  A  few  years 
suffice  to  show  them  in  actual  revolution.  Nay,  the 
movement  of  revolution  has  been  decided  before  the 
companion  star  was  discovered.  Sirius  has  long  been 
known  to  have  a  proper  motion,  such  as  it  would  have 
if  another  sun  were  revolving  about  it.  Even  the  di- 
rection of  the  unseen  body  could  always  be  indicated. 
In  February,  1862,  Alvan  Clark,  artist,  poet,  and  maker 
of  telescopes  (which  requires  even  greater  genius  than 
to  be  both  poet  and  artist),  discovered  the  companion  of 
Sirius  just  in  its  predicted  place.  As  a  matter  of  fact, 
one  of  Mr.  Clark's  sons  saw  it  first ;  but  their  fame  is 
one.  The  time  of  revolution  of  this  pair  is  fifty  years. 
But  one  companion  does  not  meet  the  conditions  of  the 
movements.  Here  must  also  be  one  or  more  planets 
too  small  or  dark  to  be  seen.  The  double  star  £  in  the 
Great  Bear  (see  Fig.  70)  makes  a  revolution  in  fifty- 
eight  years. 

Procyon  moves  in  an  orbit  which  requires  the  pres- 
ence of  a  companion  star,  but  it  has  as  yet  eluded  our 
search.  Castor  is  a  double  star;  but  a  third  star  or 
planet,  as  yet  undiscovered,  is  required  to  account  for 
its  perturbations.  Men  who  discovered  Neptune  by 
the  perturbations  of  Uranus  are  capable  of  judging  the 
cause  of  the  perturbations  of  suns.  We  have  spoken  of 


212 


THE  STELLAR  SYSTEM. 


the  whole  orbit  of  the  earth  being  invisible  from  the 
stars.  The  nearest  star  in  our  northern  hemisphere,  61 
Cygni,  is  a  telescopic  double  star  ;  the  constituent  parts 
of  it  are  forty-five  times  as  far  from  each  other  as  the 
earth  is  from  the  sun,  yet  it  takes  a  large  opera-glass  to 
show  any  distance  between  the  stars.* 

When  y  Yirginis  was  observed  in  1718  by  Bradley, 
the  component  parts  were  7"  asunder.  He  incidental- 
ly remarked  in  his  note -book  that  the  line  of  their 
connection  was  parallel  to  the  line  of  the  two  stars 
Spica,  or  a  and  S  Yirginis.  By  1840  they  were  not 
more  than  V  apart,  and  the  line  of  their  connection 
greatly  changed.  The  appearance  of  the  star  is  given 
in  Fig.  75  (15),  commencing  at  the  left,  for  the  years 
1837,  '38,  '39,  '40,  '45,  '50,  '60,  and  '79  ;  also  a  con- 
jectural orbit,  placed  obliquely,  and  the  position  of 

*  Telescopic  Work. — Only  such  work  will  be  laid  out  here  as  can  he 
done  by  small  telescopes  of  from  two  to  four  inch  object-glasses.  The 
numbers  in  Fig.  75  correspond  to  those  of  the  table. 


No. 

Name. 

H* 

Dist.  of 

Paris. 

Magni- 
tudes. 

Remarks. 

1. 

€  Lyras  

72 

I'  56" 



Quadruple. 

2. 

£  Lyras  

72 

44 

5  and  6 

Topaz  and  green. 

3. 

J3  Cvgui.... 

73 

84j 

3    "    6 

Yellow  and  blue. 

4. 

61  Cygni... 

73 

20 

5    "    6 

Nearest  star  but  one. 

5. 

Mizar  

67 

14 

3    "    4 

Both  white. 

6. 

Polaris  

67 

101 

2    "    9 

(Test  object  of  eye 
i          i    "i 

(      aim  glass. 

7. 

p  Orionis... 

Frontispiece. 

7 

5    "    8 

Yellow  and  blue. 

8. 

jSOrionis... 

9 

1    "    8 

Kigel. 

9. 

d       "     ... 

10 

2    "    8 

Red  and  white. 

10. 

0       "     ... 

Septuple. 

11. 

X       "      ... 

5 

White  and  violet. 

12. 

o       "      ... 

A,B. 

11 

4    "  10 

Octuple. 

13. 

Castor  

69 

5! 

2    "    3 

White. 

14. 

Pollux  

69 



Triple. 

Orange,  gray,  lilac. 

15. 

y  Virgin  is.. 

70 

5 

3  and  3 

Both  yellow. 

DOUBLE  AND  MULTIPLE  STARS.  213 

the  stars  at  the  times  mentioned,  commencing  at  the 
top.  The  time  of  its  complete  revolution  is  one  hun- 
dred and  fifty  years. 


Fig.  75.— Aspects  and  Revolution  of  Double  Stars. 

The  meaning  of  these  double  stars  is  that  two  or 
more  suns  revolve  about  their  centre  of  gravity,  as  the 
moon  and  earth  about  their  centre.  If  they  have  plan- 
ets, as  doubtless  they  have,  the  movement  is  no  more 
complicated  than  the  planets  we  call  satellites  of  Saturn 
revolving  about  their  central  bod}7,  and  also  about  the 
sun.  Kindle  Saturn  and  Jupiter  to  a  blaze,  or  let  out 
their  possible  light,  and  our  system  would  appear  a 
triple  star  in  the  distance.  Doubtless,  in  the  far  past, 
before  these  giant  planets  were  cooled,  it  so  appeared. 

We  find  some  stars  double,  others  triple,  quadruple, 
octuple,  and  multiple.  It  is  an  extension  of  the  same 
principles  that  govern  our  system.  Some  of  these  suns 
are  so  far  asunder  that  they  can  swing  their  Xeptunes 
between  them,  with  less  perturbation  than  Uranus  and 
Neptune  have  in  ours.  Light  all  our  planets,  and  there 
would  be  a  multiple  star  with  more  or  less  suns  seen, 


214  THE  STELLAR  SYSTEM. 

according  to  the  power  of  the  instrument.  Perhaps  the 
octuple  star  a  in  Orion  differs  in  no  respect  from  our  sys- 
tem, except  in  the  size  and  distance  of  its  separate  bod- 
ies, and  less  cooling,  either  from  being  younger,  or  from 
the  larger  bodies  cooling  more  slowly.  Suns  are  of  all 
ages.  Infinite  variety  fills  the  sky.  It  is  as  preposter- 
ous to  expect  that  every  system  or  world  should  have 
analogous  circumstances  to  ours  at  the  present  time,  as 
to  insist  that  every  member  of  a  family  should  be  of  the 
same  age,  and  in  the  same  state  of  development.  There 
are  worlds  that  have  not  yet  reached  the  conditions  of 
habitability  by  men,  and  worlds  that  have  passed  these 
conditions  long  since.  Let  them  go.  There  are  enough 
left,  arid  an  infinite  number  in  the  course  of  preparation. 
Some  are  fine  and  lasting  enough  to  be  eternal  mansions. 

Colored  Stars. 

In  the  smoky  morning  we  get  only  red  light,  but  the 
sun  is  white.  So  Aldebaran  and  Betelguese  may  be 
girt  by  vapors,  that  only  the  strong  red  rays  can  pass. 
Again,  an  iron  moderately  heated  gives  out  dull  red 
light ;  becoming  hotter,  it  emits  white  light.  Sirius, 
Regulus,  Yega,  and  Spica  may  be  white  from  greater 
intensity  of  vibration.  Procyon,  Capella,  and  Polaris 
are  yellow  from  less  intensity  of  vibration.  Again, 
burn  salt  in  a  white  flame,  and  it  turns  to  yellow;  mix 
alcohol  and  boracic  acid,  ignite  them,  and  a  beautiful 
green  flame  results;  alcohol  and  nitrate  of  strontia 
give  red  flame  ;  alcohol  and  nitrate  of  barytes  give 
yellow  flame.  So  the  composition  of  a  sun,  or  the  spe- 
cial development  of  any  one  substance  thereof  at  any 
time,  may  determine  the  color  of  a  star. 


CLUSTERS  OF  STARS.  215 

The  special  glory  of  color  in  the  stars  is  seen  in  the 
marked  contrasts  presented  in  the  double  and  multiple 
stars.  The  larger  star  is  usually  white,  still  in  the  in- 
tensity of  heat  and  vibration ;  the  others,  smaller,  are 
somewhat  cooled  off,  and  hence  present  colors  lower 
down  the  scale  of  vibration,  as  green,  yellow,  orange, 
and  even  red. 

That  stars  should  change  color  is  most  natural.  Many 
causes  would  produce  this  effect.  The  ancients  said  Si- 
rius  was  red.  It  is  now  white.  The  change  that  would 
most  naturally  follow  mere  age  and  cooling  would  be 
from  white,  through  various  colors,  to  red.  We  are 
charmed  with  the  variegated  flowers  of  our  gardens  of 
earth,  but  he  who  makes  the  fields  blush  with  flowers 
under  the  warm  kisses  of  the  sun  has  planted  his  wider 
gardens  of  space  with  colored  stars.  "  The  rainbow 
flowers  of  the  footstool,  and  the  starry  flowers  of  the 
throne,"  proclaim  one  being  as  the  author  of  them  all. 

Clusters  of  Stars. 

From  double  and  multiple  we  naturally  come  to 
groups  and  clusters.  Allusion  has  been  made  to  the 
Hyades,  Pleiades,  etc.  Every  one  has  noticed  the 
Milky  Way.  It  seems  like  two  irregular  streams  of 
compacted  stars.  It  is  not  supposed  that  they  are  nec- 
essarily nearer  together  than  the  stars  in  the  sparse  re- 
gions about  the  pole.  But  the  18,000,000  suns  belong- 
ing to  our  system  are  arranged  within  a  space  repre- 
sented by  a  flattened  disk.  If  one  hundred  lights,  three 
inches  apart,  are  arranged  on  a  hoop  ten  feet  in  diame- 
ter, they  would  be  in  a  circle.  Add  a  thousand  or  two 
more  the  same  distance  apart,  filling  up  the  centre,  and 


216 


THE  STELLAR  SYSTEM. 


ft).— Sprayed  Cluster  below  n  iu 
Hercules. 


extending  a  few  inches  on  each  side  of  the  inner  plane 
of  the  hoop :  an  eye  in  the  centre,  looking  out  toward 
the  edge,  would  see  a  milky  way  of  lights;  looking  out 

toward  the  sides  or  poles, 
would  see  comparatively 
few.  It  would  seem  as  if 
this  oblate  spheroidal  ar- 
rangement was  the  result 
of  a  revolution  of  all  the 
suns  composing  the  system. 
Jupiter  and  earth  are  flat- 
tened at  the  poles  for  the 
same  reason. 

In  various  parts  of  the 
heavens  there  are  small 
globular  well-defined  clus- 
ters, and  clusters  very  irregular  in  form,  marked  with 
sprays  of  stars.  There  is  a  cluster  of  this  latter  class  in 
Hercules,  just  under  the  S, 
in  Fig.  72.  "  Probably  no 
one  ever  saw  it  with  a 
good  telescope  without  a 
shout  of  wonder."  Here 
is  a  cluster  of  the  former 
class  represented  in  Fig.  77. 
"The  noble  globular  clus- 
ter w  Centauri  is  beyond  all 
comparison  the  richest  and 
largest  object  of  the  kind 
in  the  heavens.  Its  stars  are  literally  innumerable ;  and 
as  their  total  light,  when  received  by  the  naked  eye,  af- 
fects it  hardly  more  than  a  star  of  the  fifth  to  fourth 


Fig.  TT.— Globular  Cluster. 


NEBULA.  217 

magnitude,  the  minuteness  of  each  star  may  be  imag- 
ined." 

There  are  two  possibilities  of  thought  concerning 
these  clusters.  Either  that  they  belong  to  our  stellar 
system,  and  hence  the  stars  must  be  small  and  young, 
or  they  are  another  universe  of  millions  of  suns,  so  far 
away  that  the  inconceivable  distances  between  the  stars 
are  shrunken  to  a'hand's-breadth,  and  their  unbearable 
splendor  of  innumerable  suns  can  only  make  a  gray 
haze  at  the  distance  at  which  we  behold  them.  The 
latter  is  the  older  and  grander  thought ;  the  former  the 
newer  and  better  substantiated. 

Nebulcs. 

The  gorgeous  clusters  we  have  been  considering  ap- 
pear to  the  eye  or  the  small  telescope  as  little  cloudlets 
of  hazy  light.  One  after  another  were  resolved  into 
stars ;  and  the  natural  conclusion  was,  that  all  would 
yield  and  reveal  themselves  to  be  clustered  suns,  when 
we  had  telescopes  of  sufficient  power.  But  the  spec- 
troscope, seeing  not  merely  form  but  substance  also, 
shows  that  some  of  them  are  not  stars  in  any  sense,  but 
masses  of  glowing  gas.  Two  of  these  nebulae  are  visi- 
ble to  the  naked  eye :  one  in  Andromeda  (see  Fig.  68), 
and  one  around  the  middle  star  of  the  sword  of  Orion, 
shown  in  Fig.  78.  A  three -inch  telescope  resolves  0 
Orionis  into  the  famous  trapezium,  and  a  five-inch  in- 
strument sees  two  stars  more.  The  shape  of  the  nebula 
is  changeable,  and  is  hardly  suggestive  of  the  moulding 
influence  of  gravitation.  It  is  probably  composed  of 
glowing  nitrogen  and  hydrogen  gases.  Nebulae  are  of 
all  conceivable  shapes — circular,  annular,  oval,  lenticu- 

10 


218  THE  STELLAR  SYSTEM. 

lar,  conical,  spiral,  snake -like,  looped,  and   nameless. 
Compare  the  sprays  of  the  Crab  nebulae  above  £  Tauri, 


Fig.  78.— The  great  Nebula  about  the  multiple  Star  0  Orionis.    (See  Frontispiece.) 

seen  in  Fig.  79,  and  the  ring  nebula,  Fig.  80.  This  last 
possibly  consists  of  stars,  and  is  situated,  as  shown  in 
Fig.  81,  midway  between  )3  and  j  Lyrse. 

When  Herschel  was  sweeping  the  heavens  with  his 
telescope,  and  saw  but  few  stars,  he  often  said  to  his 
assistant,  " Prepare  to  write;  the  nebulae  are  coming." 
They  are  most  abundant  where  the  stars  are  least  so. 
A  zone  about  the  heavens  30°  wide,  with  the  Milky 
Way  in  the  centre,  would  include  one-fourth  of  the  ce- 
lestial sphere ;  but  instead  of  one-fourth,  we  find  nine- 


NEBULA.  219 

tenths  of  the  stars  in  this  zone,  and  but  one-tenth  of  the 
nebulae. 

These  immense  masses  of  unorganized  matter  are 
noticed  to  change  their  forms,  vary  their  light  greatly, 
but  not  quickly  ;  they  change  through  the  ages.  "  God 
works  slowly."  He  takes  a  thousand  years  to  lift  his 
hand  off. 


Fig.  79.— Crab  Nebula,  near  £  Tatiri.     (See  Frontispiece.) 

There  are  many  unsolved  problems  connected  with 
these  strange  bodies.  Whether  they  belong  to  our  sys- 
tem, or  are  beyond  it,  is  not  settled ;  the  weight  of  evi- 
dence leans  to  the  first  view. 


220 


THE  STELLAR  SYSTEM. 


Variable  Stars. 

Our  sun  gives  a  variable  amount  of  light,  changing 
through  a  period  of  eleven  years.     Probably  every  star, 


Fig.  80.— The  Ring  Nebnla. 


if  examined  by  methods  sufficiently  delicate  and  exact, 
would  be  found  to  be  variable.     The  variations  of  some 


VARIABLE  STARS.  221 

stars  are  so  marked  as  to  challenge  investigation.     )3 
Lyrse  (Fig.  81)  has  two  maxima  and  minima  of  light.    In 


Fig.  81.— Constellation  Lyra,  showing  place  of  the  Ring  Nebnla, 


three  days  it  rises  from  magnitude  ±%  to  3£ ;  in  a  week 
it  falls  to  4,  and  rises  to  3£ ;  and  in  three  days  more 
drops  to  4% :  it  makes  all  these  changes  in  thirteen 
days ;  but  this  period  is  constantly  increasing.  The 
variations  of  one  hundred  and  forty -three  stars  have 
been  well  ascertained. 

Mira,  or  the  Wonderful,  in  the  Whale  (Fig.  68),  is 
easily  found  when  visible.  Align  from  Capella  to  the 
Pleiades,  and  as  much  farther,  and  four  stars  will  be 
seen,  situated  thus:  *  *  *  The  right-hand  one  is 
Mira.  For  half  a  month  it  shines  as  a  star  of  the  second 
magnitude.  Then  for  three  months  it  fades  away,  and 
is  lost  to  sight ;  going  down  even  to  the  eleventh  mag- 
nitude. But  after  five  months  its  resurrection  morning 
comes;  and  in  three  months  more — eleven  months  in 
all — our  Wonderful  is  in  its  full  glory  in  the  heavens. 
But  its  period  and  brilliancy  are  also  variable.  The  star 
Megrez,  §  in  the  Great  Bear,  has  been  growing  dim 


222  THE  STELLAR  SYSTEM. 

for  a  century.  In  1836  Betelguese  was  exceedingly 
variable,  and  continued  so  till  1840,  when  the  changes 
became  much  less  conspicuous.  Algol  (Fig.  68)  has 
been  already  referred  to.  This  slowly  winking  eye 
is  of  the  second  magnitude  during  2d.  14h.  Then  it 
dozes  off  toward  sleep  for  4h.  24m.,  when  it  is  nearly 
invisible.  It  wakes  up  during  the  same  time;  so  that 
its  period  from  maximum  brilliancy  to  the  same  state 
again  is  2d.  20h.  48m.  Its  recognizable  changes  are 
within  five  or  six  hours.  As  I  write,  March  25th,  1879, 
Algol  gives  its  minimum  light  at  9h.  36m.  P.M.  It 
passes  fifteen  minima  in  43d.  13m.  There  will  therefore 
be  another  minimum  May  7th,  at  9h.49m.  Its  future 
periods  are  easy  to  estimate.  Perhaps  it  has  some  dark 
body  revolving  about  it  at  frightful  speed,  in  a  period 
of  less  than  three  days.  The  period  of  its  variability  is 
growing  shorter  at  an  increasing  rate.  If  its  variability 
is  caused  by  a  dark  body  revolving  about  it,  the  orbit  of 
that  body  is  contracting,  and  the  huge  satellite  will  soon, 
as  celestial  periods  are  reckoned,  commence  to  graze  the 
surface  of  the  sun  itself,  rebound  again  and  again,  and 
at  length  plunge  itself  into  the  central  fire.  Such  an 
event  would  evolve  heat  enough  to  make  Algol  flame 
up  into  a  star  of  the  first  magnitude,  and  perhaps  out- 
blaze  Sirius  or  Capella  in  our  winter  sky. 

None  of  the  causes  for  "these  changes  we  have  been 
able  to  conjecture  seem  very  satisfactory.  The  stars 
may  have  opaque  planets  revolving  about  them,  shut- 
ting off  their  light ;  they  may  rotate,  and  have  unequal- 
ly illuminated  sides ;  they  may  revolve  in  very  elliptical 
orbits,  so  as  to  greatly  alter  their  distance  from  us  ;  they 
may  be  so  situated  in  regard  to  zones  of  meteorites  as 


TEMPORARY,  NEW,  AXD  LOST  STARS.  223 

to  call  down  periodically  vast  showers;  but  none  or  all 
of  these  suppositions  apply  to  all  cases,  if  they  do  to  any. 

Temporary,  New,  and  Lost  Stars. 

Besides  regular  movements  to  right  and  left,  np  and 
down,  to  and  from  us — changes  in  the  intensity  of  illu- 
mination by  changes  of  distance — besides  variations  oc- 
curring at  regular  and  ascertainable  intervals,  there  are 
stars  called  temporary,  shining  awhile  and  then  disap- 
pearing ;  new,  coming  to  a  definite  brightness,  and  so 
remaining;  and  lost,  those  whose  first  appearance  was 
not  observed,  but  which  have  utterly  disappeared. 

In  November,  1572,  a  new  star  blazed  out  in  Cassio- 
peia. Its  place  is  shown  in  Fig.  67,  \  y  being  the  stars 
$  *  in  the  seat  of  the  chair,  and  S  being  the  first  one 
7  *  in  the  back.  This  star  was  visible  at  noonday, 
and  was  brighter  than  any  other  star  in  the  heavens. 
In  January,  1573,  it  was  less  bright  than  Jupiter;  in 
April  it  was  below  the  second  magnitude,  and  the  last 
of  May  it  utterly  disappeared.  It  was  as  variable  in 
color  as  in  brilliancy.  During  its  first  two  months,  the 
period  of  greatest  brightness,  it  was  dazzling  white,  then 
became  yellow,  and  finally  as  red  as  Mars  or  Aldebaran, 
and  so  expired. 

A  bright  star  was  seen  very  near  to  the  place  of  the 
Pilgrim,  as  the  star  of  1572  was  called,  in  A.D.  945  and 
1264.  A  star  of  the  tenth  magnitude  is  now  seen 
brightening  slowly  almost  exactly  in  the  same  place. 
It  is  possible  that  this  is  a  variable  star  of  a  period  of 
about  three  hundred  and  ten  years,  and  will  blaze  out 
again  about  1885. 

But  we  have  had,  within  a  few  years,  fine  opportuni- 


224:  THE  STELLAR  SYSTEM. 

ties  to  study,  with  improved  instruments,  two  new  stars. 
On  the  evening  of  May  12th,  1866,  a  star  of  the  second 
magnitude  was  observed  in  the  Northern  Crown,  where 
no  star  above  the  fifth  magnitude  had  been  twenty- 
four  hours  before.  In  Argelander's  chart  a  star  of  the 
tenth  magnitude  occupies  the  place.  May  13th  it  had 
declined  to  the  third  magnitude,  May  16th  to  the  fourth, 
May  17th  to  the  fifth,  May  19th  to  the  seventh,  May 
31st  to  the  ninth,  and  has  since  diminished  to  the  tenth. 
The  spectroscope  showed  it  to  be  a  star  in  the  usual 
condition ;  but  through  the  usual  colored  spectrum, 
crossed  with  bright  lines,  shone  four  bright  lines,  two 
of  which  indicated  glowing  hydrogen.  Here  was  plen- 
ty of  proof  that  an  unusual  amount  of  this  gas  had 
given  this  sun  its  sudden  flame.  As  the  hydrogen 
burned  out  the  star  grew  dim. 

Two  theories  immediately  presented  themselves : 
First,  that  vast  volumes  had  been  liberated  from  within 
the  orb  by  some  sudden  breaking  up  of  the  doors  of 
its  great  deeps;  or,  second,  this  star  had  precipitated 
upon  itself,  by  attraction,  some  other  sun  or  planet,  the 
force  of  whose  impact  had  been  changed  into  heat. 

Though  we  see  the  liberated  hydrogen  of  our  sun 
burst  up  with  sudden  flame,  it  can  hardly  be  supposed 
that  enough  could  be  liberated  at  once  to  increase  the 
light  and  heat  one  hundred-fold. 

In  regard  to  the  second  theory,  it  is  capable  of  proof 
that  two  suns  half  as  large  as  ours,  moving  at  a  velocity 
of  four  hundred  and  seventy-six  miles  per  second,  would 
evolve  heat  enough  to  supply  the  radiation  of  our  sun 
for  fifty  million  years.  How  could  it  be  possible  for 
a  sun  like  this  newly  blazing  orb  to  cool  off  to  such  a 


TEMPORARY,  NEW,  AND  LOST  STARS.  -         225 

degree  in  a  month?  Besides,  there  would  not  be  one 
chance  in  a  thousand  for  two  orbs  to  come  directly  to- 
gether. They  would  revolve  about  each  other  till  a 
kind  of  grazing  contact  of  grinding  worlds  would  slow- 
ly kindle  the  ultimate  heat. 

It  is  far  more  likely  that  this  star  encountered  an 
enormous  stream  of  meteoric  bodies,  or  perhaps  absorb- 
ed a  whole  comet,  that  laid  its  million  leagues  of  tail 
as  fuel  on  the  central  fire.  Only  let  it  be  remembered 
that  the  fuel  is  far  more  force  than  substance.  Allu- 
sion has  already  been  made  to  the  sudden  brightening 
of  our  sun  on  the  first  day  of  September,  1859.  That 
was  caused,  no  doubt,  by  the  fall  of  large  meteors,  fol- 
lowing in  the  train  of  the  comet  of  1843,  or  some  other 
comet.  What  the  effect  would  have  been,  had  the  whole 
mass  of  the  comet  been  absorbed,  cannot  be  imagined. 

Another  new  star  lately  appeared  in  Cygnus,  near 
the  famous  star  61 — the  first  star  in  the  northern  hem- 
isphere whose  distance  was  determined.  It  was  first 
seen  November  24th,  1876,  as  a  third  magnitude  star 
of  a  yellow  color.  By  December  2d  it  had  sunk  to  the 
fourth  magnitude,  and  changed  to  a  greenish  color.  It 
had  then  three  bright  hydrogen  lines,  the  strong  double 
sodium  line,  and  others,  which  made  it  strongly  resem- 
ble the  spectrum  of  the  chromosphere  of  our  sun.  An 
entirely  different  result  appeared  in  the  fading  of  these 
two  stars.  In  the  case  of  the  star  in  the  Crown,  the  ex- 
traordinary light  was  the  first  to  fade,  leaving  the  usual 
stellar  spectrum.  In  the  case  of  the  star  in  Cygnus,  the 
part  of  the  spectrum  belonging  to  stellar  light  was  the 
first  to  fade,  leaving  the  bright  lines ;  that  is,  the  gas 
of  one  gave  way  to  regular  starlight,  and  the  starlight 


226        *  THE  STELLAR  SYSTEM. 

of  the  other  having  faded,  the  regular  light  of  the  glow- 
ing gas  continued.  By  some  strange  oversight,  no  one 
studied  the  star  again  for  six  months.  In  September 
and  November,  1877,  the  light  of  this  star  was  found  to 
be. blue,  and  not  to  be  starlight  at  all.  It  had  no  rain- 
bow spectrum,  only  one  kind  of  rays,  and  hence  only 
one  color.  Its  sole  spectroscopic  line  is  believed  to  be 
that  of  glowing  nitrogen  gas.  We  have  then,  probably, 
in  the  star  of  1876,  a  body  shining  by  a  feeble  and  un- 
discernible  light,  surrounded  by  a  discernible  immensi- 
ty of  light  of  nitrogen  gas.  This  is  its  usual  condition ; 
but  if  a  flight  of  meteors  should  raise  the  heat  of  the 
central  body  so  as  to  outshine  the  nebulous  envelope, 
we  should  have  the  conditions  we  discovered  in  No- 
vember, 1876.  But  a  rapid  cooling  dissipates  the  ob- 
servable light  of  all  colors,  and  leaves  only  the  glowing 
gas  of  one  color. 

Movements  of  Stars. 

We  call  the  stars  fixed,  but  motion  and  life  are  nec- 
essary to  all  things.  Besides  the  motion  in  the  line  of 
sight  described  already,  there  is  motion  in  every  other 
conceivable  direction.  We  knew  Sirius  moved  before 
we  had  found  the  cause.  We  know  that  our  sun  moves 
back  and  forth  in  his  easy  bed  one-half  his  vast  diam- 
eter, as  the  larger  planets  combine  their  influence  on 
one  side  or  the  other. 

The  sun  has  another  movement.  We  find  the  stars 
in  Hercules  gradually  spreading  from  each  other.  Iler- 
cules's  brawny  limbs  grow  brawnier  every  century. 
There  can  be  but  one  cause :  we  are  approaching  that 
quarter  of  the  heavens.  (See  0,  Fig.  72.)  We  are  even 


MOVEMENTS  OF  STARS.  227 

able  to  compute  the  velocity  of  our  approach ;  it  is 
eight  miles  a  second.  The  stars  in  the  opposite  quarter 
of  the  heavens  in  the  Dove  are  drawing  nearer  together. 

This  movement  would  have  no  effect  on  the  apparent 
place  of  the  stars  at  either  pole,  if  they  were  all  equally 
distant ;  but  it  must  greatly  extend  or  contract  the  ap- 
parent space  between 'them,  since  they  are  situated  at 
various  distances. 

Independent  of  this,  the  stars  themselves  are  all  in 
motion,  but  so  vast  is  the  distance  from  which  we  ob- 
serve them  that  it  has  taken  an  accumulation  of  centu- 
ries before  they  could  be  made  measurable.  A  train 
going  forty  miles  an  hour,  seen  from  a  distance  of  two 
miles,  almost  seems  to  stand  still.  Arcturus  moves 
through  space  three  times  as  fast  as  the  earth,  but  it 
takes  a  century  to  appear  to  move  the  eighth  part  of 
the  diameter  of  the  moon.  There  is  a  star  in  the  Hunt- 
ing Dogs,  known  as  1830  Groombridge,  which  has  a 
velocity  beyond  what  all  the  attraction  of  the  matter  of 
the  known  universe  could  give  it.  By  the  year  9000 
it  may  be  in  Berenice's  Hair. 

.  Some  stars  have  a  common  movement,  being  evident- 
ly related  together.  A  large  proportion  of  the  bright- 
er stars  between  Aldebaran  and  the  Pleiades  have  a 
common  motion  eastward  of  about  ten  seconds  a  cen- 
tury. All  the  angles  marked  by  a,  )3,  7,  \  Orionis  will 
be  altered  in  different  directions;  X  is  moving  toward  y. 
A  and  £  will  appear  as  a  double  star.  In  A.D.  50,000 
Procyon  will  be  nearer  ^  Orionis  than  Rigel  now  is, 
and  Sirius  will  be  in  line  with  a  and  ^  Orionis.  All 
the  stars  of  the  Great  Dipper,  except  Benetnasch  and 
Dubhe,  have  a  common  motion  somewhat  in  the  direc- 


228  THE  STELLAR  SYSTEM. 

tion  of  Thuban  (Fig.  67),  while  the  two  named  have  a 
motion  nearly  opposite.  In  36,000  years  the  end  of 
the  Dipper  will  have  fallen  out  so  that  it  will  hold  no 
water,  arid  the  handle  will  be  broken  square  off  at  Mi- 
zar.  "  The  Southern  Cross,"  says  Humboldt,  "  will  not 
always  keep  its  characteristic  form,  for  its  four  stars 
travel  in  different  directions  with  unequal  velocities. 
At  the  present  time  it  is  not  known  how  many  myriads 
of  years  must  elapse  before  its  entire  dislocation." 

These  movements  are  not  in  fortuitous  or  chaotic 
ways,  but  are  doubtless  in  accordance  with  some  perfect 
plan.  We  have  climbed  up  from  revolving  earth  and 
moon  to  revolving  planets  and  sun,  in  order  to  under- 
stand how  two  or  ten  suns  can  revolve  about  a  common 
centre.  Let  us  now  leap  to  the  grander  idea  that  all 
the  innumerable  stars  of  a  winter  night  not  only  can, 
but  must  revolve  about  some  centre  of  gravity.  Men 
have  been  looking  for  a  central  sun  of  suns,  and  have 
not  found  it.  None  is  needed.  Two  suns  can  balance 
about  a  point;  all  suns  can  swing  about  a  common 
centre.  That  one  unmoving  centre  may  be  that  city 
more  gorgeous  than  Eastern  imagination  ever  conceived, 
whose  pavement  is  transparent  gold,  whose  walls  are 
precious  stones,  whose  light  is  life,  and  where  no  dark 
planetary  bodies  ever  cast  shadows.  There  reigns  the 
King  and  Lord  of  all,  and  ranged  about  are  the  far- 
off  provinces  of  his  material  systems.  They  all  move 
in  his  sight,  and  receive  power  from  a  mind  that  never 
wearies. 


XI. 

THE  "WORLDS  AND  THE  WORD. 
uTfte  wonas  were  framed  by  the  word  of  God." — Heb.  xi.,  3. 


•'  Mysterious  night!  when  our  first  parent  knew  thee 
From  report  divine,  and  heard  thy  name, 
Did  he  not  tremble  for  this  lovely  frame, 
This  glorious  canopy  of  light  and  blue? 
Yet,  'neath  a  curtain  of  translucent  de\v, 
Bathed  in  the  rays  of  the  great  setting  flame, 
Hesperus,  with  all  the  host  of  heaven,  car/.e. 
And  lo !   creation  widened  in  man's  view. 
Who  could  have  thought  such  darkness  lay  oonceaiec* 
Within  thy  beams,  O  Sun !     Oh  who  could  find. 
Whilst  fruit  and  leaf  and  insect  stood  revealed, 
That  to  such  countless  worlds  thou  mad'st  us  blind! 
Why  do  we  then  shun  death  with  anxious  strife? 
If  light  conceal  so  much,  wherefore  not  life?" 

BLANCO  WHITEO 


THE  WORLDS  AND   THE  WORD.  231 


XL 

THE  WORLDS  AND  THE  WORD. 

MEN  have  found  the  various  worlds  to  be  far  rich- 
er than  they  originally  thought.  They  have  opened 
door  after  door  in  their  vast  treasuries,  have  ascended 
throne  after  throne  of  power,  and  ruled  realms  of  in- 
creasing extent.  We  have  no  doubt  that  unfoldings 
in  the  future  will  amaze  even  those  whose  expectations 
have  been  quickened  by  the  revealings  of  the  past. 
What  if  it  be  found  that  the  Word  is  equally  inex- 
haustible ? 

After  ages  of  thought  and  discovery  we  have  come 
out  of  the  darkness  and  misconceptions  of  men.  We 
believe  in  no  serpent,  turtle,  or  elephant  supporting 
the  world;  no  Atlas  holding  up  the  heavens;  no  crys- 
tal domes,  "  with  cycles  and  epicycles  scribbled  o'er." 
What  if  it  be  found  that  one  book,  written  by  ignorant 
men,  never  fell  into  these  mistakes  of  the  wisest !  JS"ay, 
more,  what  if  some  of  the  greatest  triumphs  of  modern 
science  are  to  be  found  plainly  stated  in  a  book  older 
than  the  writings  of  Homer?  If  suns,  planets,  and 
satellites,  with  all  their  possibilities  of  life,  changes  of 
flora  and  fauna,  could  be  all  provided  for,  as  some 
scientists  tell  us,  in  the  fiery  star-dust  of  a  cloud,  why 
may  not  the  same  Author  provide  a  perpetually  widen- 
ing river  of  life  in  his  Word?  As  we  believe  He  is 
perpetually  present  in  his  worlds,  we  know  He  has 


232        THE  WORLDS  AND  THE  WORD. 

promised  to  be  perpetually  present  in  his  Word,  making 
it  alive  with  spirit  and  life. 

The  wise  men  of  the  past  could  not  avoid  alluding 
to  ideas  the  falsity  of  which  subsequent  discovery  has 
revealed;  but  the  writers  of  the  Bible  did  avoid  such 
erroneous  allusion.  Of  course  they  referred  to  some 
things,  as  sunrise  and  sunset,  according  to  appearance; 
but  our  most  scientific  books  do  the  same  to-day. 
That  the  Bible  could  avoid  teaching  the  opposite  of 
scientific  truth  proclaims  that  a  higher  than  human 
wisdom  was  in  its  teaching. 

That  negative  argument  is  strong,  but  the  affirmative 
argument  is  much  stronger.  The  Bible  declares  scien- 
tific truth  far  in  advance  of  its  discovery,  far  in  ad- 
vance of  man's  ability  to  understand  its  plain  declara- 
tions. Take  a  few  conspicuous  illustrations  : 

The  Bible  asserted  from  the  first  that  the  present 
order  of  things  had  a  beginning.  After  ages  of  investi- 
gation, after  researches  in  the  realms  of  physics,  argu- 
ments in  metaphysics,  and  conclusions  by  the  necessities 
of  resistless  logic,  science  has  reached  the  same  result. 

The  Bible  asserted  from  the  first  that  creation  of 
matter  preceded  arrangement.  It  was  chaos — void — 
without  form — darkness:  arrangement  was  a  subsequent 
work.  The  world  was  not  created  in  the  form  it  was 
to  have;  it  was  to  be  moulded,  shaped,  stratified,  coal- 
ed, mountained,  valleyed,  subsequently.  All  of  which 
science  utters  ages  afterward. 

The  Bible  did  not  hesitate  to  affirm  that  light  existed 
before  the  sun,  though  men  did  not  believe  it,  and 
used  it  as  a  weapon  against  inspiration.  Now  we  praise 
men  for  having  demonstrated  the  oldest  record. 


THE  WORLDS  AND   THE  WORD.  233 

It  is  a  recently  discovered  truth  of  science  that  the 
strata  of  the  earth  were  formed  by  the  action  of  water, 
and  the  mountains  were  once  under  the  ocean.  It  is 
an  idea  long  familiar  to  Bible  readers :  "  Thou  coverest 
the  earth  with  the  deep  as  with  a  garment.  The  waters 
stood  above  the  mountains.  At  thy  rebuke  they  fled ; 
at  the  voice  of  thy  thunder  they  hasted  away.  The 
mountains  ascend ;  the  valleys  descend  into  the  place 
thou  hast  founded  for  them."  Here  is  a  whole  volume 
of  geology  in  a  paragraph.  The  thunder  of  continental 
convulsions  is  God's  voice;  the  mountains  rise  by  God's 
power ;  the  waters  haste  away  unto  the  place  God  pre- 
pared for  them.  Our  slowness  of  geological  discovery 
is  perfectly  accounted  for  by  Peter.  "  For  of  this  they 
are  willingly  ignorant,  that  by  the  word  of  God  there 
were  heavens  of  old,  and  land  framed  out  of  water, 
and  by  means  of  water,  whereby  the  world  that  then 
was,  being  overflowed  by  water,  perished."  We  recog- 
nize these  geological  subsidences,  but  we  read  them 
from  the  testimony  of  the  rocks  more  willingly  than 
from  the  testimony  of  the  Word. 

Science  exults  in  having  discovered  what  it  is  pleased 
to  call  an  order  of  development  on  earth — tender  grass, 
herb,  tree ;  moving  creatures  that  have  life  in  the  wa- 
ters ;  bird,  reptile,  beast,  cattle,  man.  The  Bible  gives 
the  same  order  ages  before,  and  calls  it  God's  successive 
creations. 

During  ages  on  ages  man's  wisdom  held  the  earth  to 
be  flat.  Meanwhile,  God  was  saying,  century  after  cen- 
tury, of  himself,  "He  sitteth  upon  the  sphere  of  the 
earth  "  (Gesenins). 

Men  racked  their  feeble  wits  for  expedients  to  up- 


234:  THE  WORLDS  AND   THE  WORD. 

liold  the  earth,  and  the  best  they  could  devise  were  ser- 
pents, elephants,  and  turtles ;  beyond  that  no  one  had 
ever  gone  to  see  what  supported  them.  Meanwhile, 
God  was  perpetually  telling  men  that  he  had  hung  the 
earth  upon  nothing. 

Men  were  ever  trying  to  number  the  stars.  Hippar- 
chus  counted  one  thousand  and  twenty-two;  Ptolemy 
one  thousand  and  twenty-six;  and  it  is  easy  to  number 
those  visible  to  the  naked  eye.  But  the  Bible  said, 
when  there  were  no  telescopes  to  make  it  known,  that 
they  were  as  the  sands  of  the  sea,  "  innumerable."  Sci- 
ence has  appliances  of  enumeration  unknown  to  other 
ages,  but  the  space-penetrating  telescopes  ami  tastime- 
ters  reveal  more  worlds — eighteen  millions  in  a  single 
system,  and  systems  beyond  count — till  men  acknowl- 
edge that  the  stars  are  innumerable  to  man.  It  is 
God's  prerogative  "  to  number  all  the  stars ;  he  also 
calleth  them  all  by  their  names." 

Torricelli's. discovery  that  the  air  had  weight  was  re- 
ceived wTith  incredulity.  For  ages  the  air  had  propelled 
ships,  thrust  itself  against  the  bodies  of  men,  and  over- 
turned their  works.  But  no  man  ever  dreamed  that 
weight  was  necessary  to  give  momentum.  During  all 
the  centuries  it  had  stood  in  the  Bible,  waiting  for 
man's  comprehension:  "He  gave  to  the  air  its  weight" 
(Job  xxviii.  25). 

The  pet  science  of  to-day  is  meteorology.  The  fluc- 
tuations and  variations  of  the  weather  have  hitherto 
baffled  all  attempts  at  unravelling  them.  It  has  seemed 
that  there  was  no  law  in  their  tickle  changes.  But  at 
length  perseverance  and  skill  have  triumphed,  and  a 
single  man  in  one  place  predicts  the  weather  and  winds 


THE  WORLDS  AND   THE  WORD.  235 

for  a  continent.  But  the  Bible  has  always  insisted  that 
the  whole  department  was  under  law ;  nay,  it  laid  down 
that  law  so  clearly,  that  if  men  had  been  willing  to  learn 
from  it  they  might  have  reached  this  wisdom  ages  ago. 
The  whole  moral  law  is  not  more  clearly  crystallized  in 
"  Thou  shalt  love  the  Lord  thy  God  with  all  thy  heart, 
and  thy  neighbor  as  thyself,"  than  all  the  fundamentals 
of  the  science  of  meteorology  are  crystallized  in  these 
words :  "  The  wind  goeth  toward  the  south  (equator), 
and  turneth  about  (up)  unto  the  north ;  it  whirleth 
about  continually,  and  the  wind  returneth  again  accord- 
ing to  his  circuits  (established  routes).  All  the  rivers 
run  into  the  sea ;  yet  the  sea  is  not  full :  unto  the  place 
from  whence  the  rivers  come,  thither  they  return  again" 
(Eccles.  i.  6,  7). 

Those  scientific  queries  which  God  propounded  to 
Job  were  unanswerable  then ;  most  of  them  are  so 
now.  "  Whereon  are  the  sockets  of  the  earth  made  to 
sink?"  Job  never  knew  the  earth  turned  in  sockets; 
much  less  could  he  tell  where  they  were  fixed.  God 
answered  this  question  elsewhere.  "  He  stretcheth  the 
north  (one  socket)  over  the  empty  place,  and  hangeth 
the  earth  upon  nothing."  Speaking  of  the  day-spring, 
God  says  the  earth  is  turned,  to  it,  as  clay  to  the  seal. 
The  earth's  axial  revolution  is  clearly  recognized.  Co- 
pernicus declared  it  early  ;  God  earlier. 

K"o  man  yet  understands  the  balancing  of  the  clouds, 
nor  the  suspension  of  the  frozen  masses  of  hail,  any 
more  than  Job  did. 

Had  God  asked  if  he  hud  perceived  the  length  of  the 
earth,  many  a  man  to-day  could  have  answered  yes. 
But  the  eternal  ice  keeps  us  from  perceiving  the  breadth 


236  THE  WORLDS  AND   THE  WORD. 

of  the  earth,  and  shows  the  discriminating  wisdom  of 
the  question. 

The  statement  that  the  sun's  going  is  from  the  end 
of  the  heaven,  and  his  circuit  to  the  ends  of  it,  has  given 
edge  to  many  a  sneer  at  its  supposed  assertion  that  the 
sun  went  round  the  earth.  It  teaches  a  higher  truth— 
that  the  sun  itself  obeys  the  law  it  enforces  on  the  plan- 
ets, and  flies  in  an  orbit  of  its  own,  from  one  end  of 
heaven  in  Argo  to  the  other  in  Hercules. 

So  eminent  an  astronomer  and  so  true  a  Christian  as 
General  Mitchell,  who  understood  the  voices  in  which 
the  heavens  declare  the  glory  of  God,  who  read  with 
delight  the  Word  of  God  embodied  in  worlds,  and  who 
fed  upon  the  written  Word  of  God  as  his  daily  bread, 
declared,  "  We  find  an  aptness  and  propriety  in  all  these 
astronomical  illustrations,  which  are  not  weakened,  but 
amazingly  strengthened,  when  viewed  in  the  clear  light 
of  our  present  knowledge."  Herschel  says,  "All  hu- 
man discoveries  seem  to  be  made  only  for  the  purpose 
of  confirming  more  strongly  the  truths  that  come  from 
on  high,  and  are  contained  in  the  sacred  writings." 
The  common  authorship  of  the  worlds  and  the  Word 
becomes  apparent ;  their  common  unexplorable  wealth 
is  a  necessary  conclusion. 

Since  the  opening  revelations  of  the  past  show  an 
unsearchable  wisdom  in  the  Word,  has  that  Word  any 
prophecy  concerning  mysteries  not  yet  understood,  and 
events  yet  in  the  future  ?  There  are  certain  problems 
as  yet  insolvable.  We  have  grasped  many  clews,  and 
followed  them  far  into  labyrinths  of  darkness,  but  not 
yet  through  into  light. 

We  ask  in  vain,  "  What  is  matter  ?"     No  man  can 


THE  WORLDS  AXD    THE  WORD.  237 

answer.  We  trace  it  up  through  the  worlds,  till  its  in- 
creasing fineness,  its  growing  power,  and  possible  iden- 
tity of  substance,  seem  as  if  the  next  step  would  reveal 
its  spirit  origin.  What  we  but  hesitatingly  stammer, 
the  Word  boldly  asserts. 

We  ask,  "  What  is  force  ?"  No  man  can  answer. 
We  recognize  its  various  grades,  each  subordinate  to 
the  higher — cohesion  dissolvable  by  heat;  the  affinity 
of  oxygen  and  hydrogen  in  water  overcome  by  the  pierc- 
ing intensity  of  electric  fire ;  rivers  seeking  the  sea  by 
gravitation  carried  back  by  the  sun;  rock  turned  to 
soil,  soil  to  flowers ;  and  all  the  forces  in  nature  meas- 
urably subservient  to  iniiid.  Hence  we  partly  under- 
stand what  the  Word  has  always  taught  us,  that  all 
lower  forces  must  be  subject  to  that  which  is  highest. 
How  easily  can  seas  be  divided,  iron  made  to  swim, 
water  to  burn,  and  a  dead  body  to  live  again,  if  the 
highest  force  exert  itself  over  forces  made  to  be  mas- 
tered. When  we  have  followed  force  to  its  highest 
place,  we  always  find  ourselves  considering  the  forces 
of  mind  and  spirit,  and  say,  in  the  words  of  the  Scrip- 
tures, "  God  is  spirit." 

We  ask  in  vain  what  is  the  end  of  the  present  condi- 
tion of  things.  We  have  read  the  history  of  our  globe 
with  great  difficulty — its  prophecy  is  still  more  difficult. 
We  have  asked  whether  the  stars  form  a  system,  and 
if  so,  whether  that  system  is  permanent.  We  are  not 
able  to  answer  yet.  We  have  said  that  the  sun  would 
in  time  become  as  icy  cold  and  dead  as  the  moon,  and 
then  the  earth  would  wander  darkling  in  the  voids  of 
space.  But  the  end  of  the  earth,  as  prophesied  in  the 
Word,  is  different :  "  The  heavens  will  pass  away  witli 


238  THE  WORLDS  AND    THE  WORD. 

a  rushing  noise,  and  the  elements  will  be  dissolved  with 
burning  heat,  and  the  earth  arid  the  works  therein  will 
be  burned  np."  The  latest  conclusions  of  science  point 
the  same  way.  The  great  zones  of  uncondensed  matter 
about  the  sun  seem  to  constitute  a  resisting  medium  as 
far  as  they  reach.  Encke's  comet,  whose  orbit  comes 
near  the  sun,  is  delayed.  This  gives  gravitation  an 
overwhelming  power,  and  hence  the  orbit  is  lessened 
and  a  revolution  accomplished  more  quickly.  Faye's 
comet,  which  wheels  beyond  the  track  of  Mars,  is  not 
retarded.  If  the  earth  moves  through  a  resisting  sub- 
stance, its  ultimate  fall  into  the  sun  is  certain.  Wheth- 
er in  that  far  future  the  sun  shall  have  cooled  off,  or 
will  be  still  as  hot  as  to-day,  Peter's  description  would 
admirably  portray  the  result  of  the  impact.  Peter's 
description,  however,  seems  rather  to  indicate  an  inter- 
ference of  Divine  power  at  an  appropriate  time  before 
a  running  down  of  the  system  at  present  in  existence, 
and  a  re-endowment  of  matter  with  new  capabilities. 

After  thousands  of  years,  science  discovered  the  true 
way  to  knowledge.  It  is  the  Baconian  way  of  experi- 
ment, of  trial,  of  examining  the  actual,  instead  of  imag- 
ining the  ideal.  It  is  the  acceptance  of  the  Scriptural 
plan.  "  If  a  man  wills  to  do  God's  will,  he  shall  know." 
Oh  taste  and  see !  In  science  men  try  hypotheses,  think 
the  best  they  can,  plan  broadly  as  possible,  and  then  see 
if  facts  sustain  the  theory.  They  have  adopted  the 
Scriptural  idea  of  accepting  a  plan,  and  then  working 
in  faith,  in  order  to  acquire  knowledge.  Fortunately, 
in  the  work  of  salvation  the  plan  is  always  perfect. 
But,  in  order  to  make  the  trial  under  the  most  favora- 
ble circumstances,  there  must  be  faith.  The  faith  of 


THE  WORLDS  AXD  THE  WORD.        239 

science  is  amazing;  its  assertions  of  the  supersensual 
are  astounding.  It  affirms  a  thousand  things  that  can- 
not be  physically  demonstrated :  that  the  flight  of  a  rifle- 
ball  is  parabolic ;  that  the  earth  has  poles ;  that  gases  are 
made  of  particles;  that  there  are  atoms;  that  an  elec- 
tric light  gives  ten  times  as  many  rays  as  are  visible; 
that  there  are  sounds  to  which  we  are  deaf,  sights  to 
which  we  are  blind ;  that  a  thousand  objects  and  activi- 
ties are  about  us,  for  the  perception  of  which  we  need  a 
hundred  senses  instead  of  five.  These  faiths  have  near- 
ly all  led  to  sight ;  they  have  been  rewarded,  and  the 
world's  wealth  of  knowledge  is  the  result.  The  Word 
has  ever  asserted  the  supersensuous,  solicited  man's  faith, 
and  ever  uplifted  every  true  faith  into  sight.  Lowell  is 
partly  right  when  he  sings : 

"Science  was  Faith  once;   Faith  were  science  now, 
Would  she  but  lav  her  bow  and  arrows  by, 
And  arm  her  with  the  weapons  of  the  time." 

Faith  laid  her  bow  and  arrows  by  before  men  in  pursuit 
of  worldly  knowledge  discovered  theirs. 

What  becomes  of  the  force  of  the  sun  that  is  being 
spent  to-day  ?  It  is  one  of  the  firmest  rocks  of  science 
that  there  can  be  no  absolute  destruction  of  force.  It 
is  all  conserved  somehow.  But  how  ?  The  sun  con- 
tracts, light  results,  and  leaps  swiftly  into  all  encircling 
space.  It  can  never  be  returned.  Heat  from  stars  in- 
visible by  the  largest  telescope  enters  the  tasti meter,  and 
declares  that  that  force  has  journeyed  from  its  source 
through  incalculable  years.  There  is  no  encircling 
dome  to  reflect  all  this  force  back  upon  its  sources.  Is 
it  lost  (  Science,  in  defence  of  its  own  dogma,  should 


240  THE  WORLDS  AND    THE  WORD. 

assign  light  a  work  as  it  flies  in  the  space  which  we  have 
learned  cannot  be  empty.  There  ought  to  be  a  realm 
where  light's  inconceivable  energy  is  utilized  in  build- 
ing a  grander  universe,  where  there  is  no  night.  Christ 
said,  as  he  went  out  of  the  seen  into  the  unseen,  "  I  go 
to  prepare  a  place  for  you ;"  and  when  John  saw  it  in 
•vision  the  sun  had  disappeared,  the  moon  was  gone,  but 
the  light  still  continued. 

Science  finds  matter  to  be  capable  of  unknown  refine- 
ment ;  water  becomes  steam  full  of  amazing  capabilities : 
we  add  more  heat,  superheat  the  steam,  and  it  takes  on 
new  aptitudes  and  uncontrollable  energy.  Zinc  burned 
in  acid  becomes  electricity,  which  enters  iron  as  a  kind 
of  soul,  to  fill  all  that  body  with  life.  All  matter  is 
capable  of  transformation,  if  not  transfiguration,  till  it 
shines  by  the  light  of  an  indwelling  spirit.  Scripture 
readers  know  that  bodies  and  even  garments  can  be 
transfigured,  be  made  aarpcurTtov  (Luke  xxiv.  4),  shin- 
ing with  an  inner  light.  They  also  look  for  new  heav- 
ens and  a  new  earth  endowed  with  higher  powers,  fit 
for  perfect  beings. 

When  God  made  matter,  so  far  as  our  thought  per- 
mits us  to  know,  he  simply  made  force  stationary  and 
unconscious.  Thereafter  he  moves  through  it  with  his 
own  will.  He  can  at  any  time  change  these  forces, 
making  air  solid,  water  and  rock  gaseous,  a  world  a 
cloud,  or  a  fire-mist  a  stone.  He  may  at  some  time  re- 
store all  force  to  consciousness  again,  and  make  every 
part  of  the  universe  thrill  with  responsive  joy.  "  Then 
shall  the  mountains  and  the  hills  break  forth  before 
you  into  singing,  and  all  the  trees  of  the  field  clap  their 
hands."  One  of  these  changes  is  to  come  to  the  earth. 


THE  WORLDS  AXD   THE  WORD. 

Amidst  great  noise  the  heaven  shall  flee,  the  earth  be 
burned  up,  and  all  their  forces  be  changed  to  new 
forms.  Perhaps  it  will  not  then  be  visible  to  mortal 
eyes.  Perhaps  force  will  then  be  made  conscious,  and 
the  flowers  thereafter  return  our  love  as  much  as  lower 
creatures  do  now.  A  river  and  tree  of  life  may  be 
consciously  alive,  as  well  as  give  life.  Poets  that  are 
nearest  to  God  are  constantly  hearing  the  sweet  voices 
of  responsive  feeling  in  nature. 

"For  his  gayer  hours 
She  has  a  voice  of  gladness  and  a  smile, 
And  eloquence  of  beauty;  and  she  ^li.les 
Into  his  darker  musings  with  a  mild 
And  gentle  sympathy,  that  steals  away 
Their  sharpness  ere  lie  is  aware." 

Prophets  who  utter  God's  voice  of  truth  say,  "  The 
wilderness  and  the  solitary  place  shall  be  glad  for  holy 
men,  and  the  desert  shall  rejoice  and  blossom  as  the 
rose.  It  shall  blossom  abundantly  and  rejoice,  even 
with  joy  and  singing." 

Distinguish  clearly  between  certainty  .and  surmise. 
The  certainty  is  that  the  world  will  pass  through  catas- 
trophic changes  to  a  perfect  world.  The  grave  of  uni- 
fonnitarianism  is  already  covered  with  grass.  He  that 
creates  promises  to  complete.  The  invisible,  impon- 
derable, inaudible  ether  is  beyond  our  apprehension ; 
it  transmits  impressions  186,000  miles  a  second ;  it  is 
millions  of  times  more  capable  and  energetic  than  air. 
What  may  be  the  bounds  of  its  possibility  none  can  im- 
agine, for  law  is  not  abrogated  nor  designs  disregarded 
as  we  ascend  into  higher  realms.  Law  works  out  more 
beautiful  designs  with  more  absolute  certainty.  Why 

11 


242  THE  WORLDS  AND   THE  WORD. 

should  there  not  be  a  finer  universe  than  this,  and  dis- 
connected from  this  world  altogether — a  fit  home  for 
immortal  souls  ?  It  is  a  necessity. 

God  filleth  all  in  all,  is  everywhere  omnipotent  and 
wise.  Why  should  there  be  great  vacuities,  barren  of 
power  and  its  creative  outgoings  ?  God  has  fixed  the 
stars  as  proofs  of  his  agency  at  some  points  in  space. 
But  is  it  in  points  only?  Science  is  proud  of  its  dis- 
covery that  what  men  once  thought  to  be  empty  space 
is  more  intensely  active  than  the  coarser  forms  of  mat- 
ter can  be.  But  in  the  long  times  which  are  past  Job 
glanced  at  earth,  seas,  clouds,  pillars  of  heaven,  stars, 
day,  night,  all  visible  things,  and  then  added:  "Lo! 
these  are  only  the  outlying  borders  of  his  works.  AVhat 
a  wThisper  of  a  word  we  hear  of  Him  !  The  thunder 
of  his  power  who  can  comprehend  ?" 

Science  discovers  that  man  is  adapted  for  mastery  in 
this  world.  He  is  of  the  highest  order  of  visible  creat- 
ures. Neither  is  it  possible  to  imagine  an  order  of  be- 
ings generically  higher  to  be  connected  with  the  con- 
ditions of  the.  material  world.  This  whole  secret  wras 
known  to  the  author  of  the  oldest  writing.  "  And  God 
blessed  them,  and  God  said  unto  them:  Be  fruitful,  and 
multiply,  and  replenish  the  earth,  and  subdue  it :  and 
have  dominion  over  the  fish  of  the  sea,  and  over  the 
fowl  of  the  air,  and  over  every  living  thing  that  moveth 
upon  the  earth."  The  idea  is  never  lost  sight  of  in  the 
sacred  writings.  And  while  every  rnan  knows  he  must 
fail  in  one  great  contest,  and  yield  himself  to  death, 
the  later  portions  of  the  divine  Word  offer  him  victory 
even  here.  The  typical  man  is  commissioned  to  destroy 
even  death,  and  make  man  a  sharer  in  the  victory. 


THE  WORLDS  AND   THE  WORD. 

Science  babbles  at  this  great  truth  of  man's  position 
like  a  little  child ;  Scripture  treats  it  with  a  breadth  of 
perfect  wisdom  we  are  only  beginning  to  grasp. 

Science  tells  us  that  each  type  is  prophetic  of  a 
higher  one.  The  whale  has  bones  prophetic  of  a 
human  hand.  Has  man  reached  perfection?  Is  there 
no  prophecy  in  him  ?  Not  in  his  body,  perhaps ;  but 
how  his  whole  soul  yearns  for  greater  beauty.  As 
soon  as  he  has  found  food,  the  savage  begins  to  carve 
his  paddle,  and  make  himself  gorgeous  with  feathers. 
How  man  yearns  for  strength,  subduing  animal  and 
cosmic  forces  to  his  will !  How  he  fights  against  dark- 
ness and  death,  and  strives  for  perfection  and  holiness ! 
These  prophecies  compel  us  to  believe  there  is  a  world 
where  powers  like  those  of  electricity  and  luminiferous 
ether  are  ever  at  hand;  where  its  waters  are  rivers  of 
life,  and  its  trees  full  of  perfect  healing,  and  from  which 
all  unholiness  is  forever  kept.  What  we  infer,  Scrip- 
ture affirms. 

Science  tells  us  there  has  been  a  survival  of  the  fittest. 
Doubtless  this  is  so.  So  in  the  future  there  will  be  a 
survival  of  the  fittest.  What  is  it  ?  Wisdom,  gentle- 
ness, meekness,  brotherly  kindness,  and  charity.  Over 
those  who  have  these  traits  death  hath  no  permanent 
power.  The  caterpillar  has  no  fear  as  he  weaves  his 
own  shroud  ;  for  there  is  life  within  fit  to  survive,  and 
ere  long  it  spreads  its  gorgeous  wings,  and  flies  in  the 
air  above  where  once  it  crawled.  Man  has  had  two 
states  of  being  alread3T.  One  confined,  dark,  peculiarly 
nourished,  slightly  conscious ;  then  he  was  born  into 
another — wide,  differently  nourished,  and  intensely  con- 
scious. He  knows  he  may  be  born  again  into  a  life 


244  THE  WORLDS  AND   THE  WORD. 

wider  yet,  differently  nourished,  and  even  yet  more  in- 
tensely conscious.  Science  lias  no  hint  how  a  long 
ascending  series  of  developments  crowned  by  man  may 
advance  another  step,  and  make  man  IvayysXoz — equal 
to  angels.  But  the  simplest  teaching  of  Scripture  points 
out  a  way  so  clear  that  a  child  need  not  miss  the  glori- 
ous consummation. 

When  Uranus  hastened  in  one  part  of  its  orbit, 
and  then  retarded,  and  swung  too  wide,  men  said  there 
must  be  another  attracting  world  beyond  ;  and,  looking 
there,  Neptune  was  found.  So,  wrhen  individual  men 
are  so  strong  that  nations  or  armies  cannot  break  down 
their  wills ;  so  brave,  that  lions  have  no  terrors ;  so 
holy,  that  temptation  cannot  lure  nor  sin  defile  them ; 
so  grand  in  thought,  that  men  cannot  follow ;  so  pure 
in  walk,  that  God  walks  with  them — let  us  infer  an  at- 
tracting world,  high  and  pure  and  strong  as  heaven. 
The  eleventh  chapter  of  Hebrews  is  a  roll-call  of  heroes 
of  whom  this  world  was  not  worthy.  They  were  tort- 
ured, not  accepting  deliverance,  that  they  might  obtain 
a  better  resurrection.  The  world  to  come  influenced, 
as  it  were,  the  orbits  of  their  souls,  and  when  their  bod- 
ies fell  off,  earth  having  no  hold  on  them,  they  sped  on 
to  their  celestial  home.  The  tendency  of  such  souls 
necessitates  such  a  world. 

The  worlds  and  the  Word  speak  but  one  language, 
teach  but  one  set  of  truths.  How  was  it  possible  that 
the  writers  of  the  earlier  Scriptures  described  physical 
phenomena  with  wonderful  sublimity,  and  with  such 
penetrative  truth  ?  They  gazed  upon  the  same  heaven 
that  those  men  saw  who  ages  afterward  led  the  world 
in  knowledge.  These  latter  were  near-sighted,  and  ab- 


THE  WORLDS  AND   THE  WORD.  245 

sorbed  in  the  pictures  on  the  first  veil  of  matter ;  the 
former  were  far-sighted,  and  penetrated  a  hundred 
strata  of  thickest  material,  and  saw  the  immaterial  pow- 
er behind.  The  one  class  studied  the  present,  and  made 
the  gravest  mistakes ;  the  other  pierced  the  uncounted 
ages  of  the  past,  and  uttered  the  profoundest  wisdom. 
There  is  but  one  explanation.  He  that  planned  and 
made  the  worlds  inspired  the  Word. 

Science  and  religion  are  not  two  separate  depart- 
ments, they  are  not  even  two  phases  of  the  same  truth. 
Science  has  a  broader  realm  in  the  unseen  than  in  the 
seen,  in  the  source  of  power  than  in  the  outcomes  of 
power,  in  the  sublime  laws  of  spirit  than  in  the  laws  of 
matter;  and  religion  sheds  its  beautiful  light  over  all 
stages  of  life,  till,  whether  we  eat  or  whether  we  drink, 
or  whatsoever  we  do,  we  may  do  all  for  the  glory  of 
God.  Science  and  religion  make  common  confession 
that  the  great  object  of  life  is  to  learn  and  to  grow. 
Both  will  come  to  see  the  best  possible  means,  for  the 
attainment  of  this  end  is  a  personal  relation  to  a  teach- 
er who  is  the  Way,  the  Truth,  and  the  Life. 


XII. 

THE  ULTIMATE  FORCE. 

"In  the  beginning  was  the  Word,  and  the  Word  was  with  God,  and 
the  Word  was  God.  The  same  was  in  the  beginning  with  God.  All 
tilings  became  by  him,  and  without  him  was  not  anything  made  that  was 
made  *  *  *  and  bv  nim  all  things  stand  together." 


"  O  thou  eternal  one ;  whose  presence  bright 
All  space  doth  occupy — all  motion  guide — 
Thou  from  primeval  nothingness  didst  call 
First  chaos,  then  existence.     Lord,  on  thee 
Eternity  had  its  foundation  :  all 
Sprung  forth  from  thee — of  light,  joy,  harmony, 
Sole  origin  :  all  life,  all  beauty  thine. 
Thy  word  created  all,  and  doth  create ; 
Thy  splendor  fills  all  space  with  rays  divine ; 
Thou  art  and  wert,  and  shalt  be  glorious,  great ; 
Life-giving,  life-sustaining  Potentate, 
Thy  chains  the  unmeasured  universe  surround — 
Upheld  by  thee,  by  thee  inspired  with  breath." 

DlCRZHAVIN 


THE  ULTIMATE  FORCE.  249 


XII. 
THE    ULTIMATE  FORCE. 

THE  universe  is  God's  name  writ  large.  Thought 
goes  up  the  shining  suns  as  golden  stairs,  and  reads  the 
consecutive  syllables — all  might,  and  wisdom,  and  beau- 
ty; and  if  the  heart  be  fine  enough  and  pure  enough,  it 
also  reads  everywhere  the  mystic  name  of  love.  Let 
us  learn  to  read  the  hieroglyphics,  and  then  turn  to  the 
blazonry  of  the  infinite  page.  That  is  the  key-note;  the 
heavens  and  the  earth  declaring  the  glory  of  God,  and 
men  with  souls  attuned  listening.  • 

To  what  voices  shall  we  listen  first?  Stand  on  the 
shore  of  a  lake  set  like  an  azure  gem  among  the  bosses 
of  green  hills.  The  patter  of  rain  means  an  annual  fall 
of  four  cubic  feet  of  water  on  every  square  foot  of  it. 
It  weighs  sixty-two  and  three-tenths  pounds  to  the  cubic 
foot,  i.  e.y  fifty-two  million  tons  on  the  surface  of  a  little 
sheet  of  water  twenty  miles  long  by  three  wide.  Now, 
all  that  weight  of  falling  rain  had  to  be  lifted,  a  work 
compared  to  which  taking  up  mountains  and  casting 
them  into  the  sea  is  pastime.  All  that  water  had  to  be 
taken  up  before  it  could  be  cast  down,  and  carried  hun- 
dreds of  miles  before  it  could  be  there.  You  have  heard 
Niagara's  thunder;  have  stood  beneath  the  falling  im- 
mensity; seen  it  ceaselessly  poured  from  an  infinite 
hand ;  felt  that  you  would  be  ground  to  atoms  if  you 
fell  into  that  resistless  flood.  Well,  all  that  infinity  of 

11* 


250  THE  ULTIMATE  FORCE. 

water  had  to  be  lifted  by  main  force,  Lad  to  be  taken 
up  out  of  the  far  Pacific,  brought  over  the  Rocky 
Mountains ;  and  the  Mississippi  keeps  bearing  its  wide 
miles  of  water  to  the  Gulf,  and  Niagara  keeps  thunder- 
ing age  after  age,  because  there  is  power  somewhere  to 
carry  the  immeasurable  floods  all  the  time  the  other 
way  in  the  upper  air. 

But  this  is  only  the  Alpha  of  power.  Professor 
Clark,  of  Amherst,  Massachusetts,  found  that  such  a 
soft  and  pulpy  thing  as  a  squash  had  so  great  a  power 
of  growth  that  it  lifted  three  thousand  pounds,  arid  held 
it  day  and  night  for  months.  It  toiled  and  grew  un- 
der the  growing  weight,  compacting  its  substance  like 
oak  to  do  the  work.  All  over  the  earth  this  tremen- 
dous power  and  push  of  life  goes  on — in  the  little  star- 
eyed  flowers  that  look  up  to  God  only  on  the  Alpine 
heights,  in  every  tuft  of  grass,  in  every  acre  of  wheat, 
in  every  mile  of  prairie,  and  in  every  lofty  tree  that 
wrestles  with  the  tempests  of  one  hundred  winters. 
But  this  is  only  the  B  in  the  alphabet  of  power. 

Rise  above  the  earth,  and  you  find  the  worlds  tossed 
like  playthings,  and  hurled  seventy  times  as  fast  as  a 
rifle-ball,  never  an  inch  out  of  place  or  a  second  out  of 
time.  But  this  is  only  the  C  in  the  alphabet  of  power. 

Rise  to  the  sun.  It  is  a  quenchless  reservoir  of  high- 
class  energy.  Our  tornadoes  move  sixty  miles  an  hour, 
those  of  the  sun  twenty  thousand  miles  an  hour.  A 
forest  on  fire  sends  its  spires  of  flame  one  hundred  feet 
ifl  air,  the  sun  sends  its  spires  of  flame  two  hundred 
thousand  miles.  All  our  fires  exhaust  the  fuel  and  burn 
out.  If  the  sun  were  pure  coal,  it  would  burn  out  in 
five  thousand  years ;  and  yet  this  sea  of  unquenchable 


THE  ULTIMATE  FORCE.  251 

flame  seethes  and  burns,  and  rolls  and  vivifies  a  dozen 
worlds,  and  flashes  life  along  the  starry  spaces  for  a  mill- 
ion years  without  any  apparent  diminution.  .  It  sends 
out  its  power  to  every  planet,  in  the  vast  circle  in  which 
it  lies.  It  fills  with  light  not  merely  a  whole  circle,  but 
a  dome ;  not  merely  a  dome  above,  but  one  below,  and 
on  every  side.  At  our  distance  of  ninety-two  and  a  half 
millions  of  miles,  the  great  earth  feels  that  power  in 
gravitation,  tides,  rains,  winds,  and  all  possible  life — 
every  part  is  full  of  power.  Fill  the  earth's  orbit  with 
a  circle  of  such  receptive  worlds — seventy  thousand  in- 
stead of  one — every  one  would  be  as  fully  supplied  with 
power  from  this  central  source.  More.  Fill  the  whole 
dome,  the  entire  extent  of  the  surrounding  sphere,  bot- 
tom, sides,  top,  a  sphere  one  hundred  and  eighty -five 
million  miles  in  diameter,  and  every  one  of  these  un- 
countable worlds  would  be  touched  with  the  same  pow- 
er as  one;  each  would  thrill  with  life.  This  is  only  the 
D  of  the  alphabet  of  power.  And  glancing  up  to  the 
other  suns,  one  hundred,  five  hundred,  twelve  hundred 
times  as  large,  double,  triple,  septuple,  multiple  suns,  we 
shall  find  power  enough  to  go  through  the  whole  alpha- 
bet in  geometrical  ratio ;  and  then  in  the  clustered  suns, 
galaxies,  and  nebulae,  power  enough  still  unrepresented 
by  single  letters  to  require  all  combinations  of  the  al- 
phabet of  power.  What  is  the  significance  of  this  single 
element  of  power  ?  The  answer  of  science  to-day  is  "  cor- 
relation," the  constant  evolution  of  one  force  from  an- 
other. Heat  is  a  mode  of  motion,  motion  a  result  of  heat. 
So  far  so  good.  But  are  we  mere  reasoners  in  a  circle? 
Then  we  would  be  lost  men,  treading  our  round  of  death 
in  a  limitless  forest.  What  is  the  ultimate?  Reason 


252  THE  ULTIMATE  FORCE. 

out  in  a  straight  line.  No  definition  of  matter  allows  it 
to  originate  force ;  only  mind  can  do  that.  Hence  the 
ultimate  .force  is  always  mind.  Carry  your  correlation 
as  far  as  you  please — through  planets,  suns,  nebulae,  con- 
cretionary vortices,  and  revolving  fire-mist — there  must 
always  be  mind  and  will  beyond.  Some  of  that  will- 
power that  works  without  exhaustion  must  take  its  own 
force  and  render  it  static,  apparent.  It  may  do  this  in 
such  correlated  relation  that  that  force  shall  go  on  year 
after  year  to  a  thousand  changing  forms;  but  that  force 
must  originate  in  mind. 

Go  out  in  the  falling  rain,  stand  under  the  thunder- 
ous Niagara,  feel  the  immeasurable  rush  of  life,  see  the 
hanging  worlds,  and  trace  all  this — the  carried  rain,  the 
terrific  thunder  with  God's  bow  of  peace  upon  it,  and 
the  unfailing  planets  hung  upon  nothing — trace  all  this 
to  the  orb  of  day  blazing  in  perpetual  strength,  but  stop 
not  there.  Who  made  the  sun  ?  Contrivance  fills  all 
thought.  Who  made  the  sun  ?  Nature  says  there  is  a 
mind,  and  that  mind  is  Almighty.  Then  you  have  read 
the  first  syllables,  viz.,  being  and  power. 

What  is  the  continuous  relation  of  the  universe  to  the 
mind  from  which  it  derived  its  power?  Some  say  that 
it  is  the  relation  of  a  wound-up  watch  to  the  winder.  It 
was  dowered  with  sufficient  power  to  revolve  its  cease- 
less changes,  and  its  maker  is  henceforth  an  absentee 
God.  Is  it  ?  Let  us  have  courage  to  see.  For  twen- 
ty years  one  devotes  ten  seconds  every  night  to  put- 
ting a  little  force  into  a  watch.  It  is  so  arranged  that 
it  distributes  that  force  over  twenty -four  hours.  In 
that  twenty  years  more  power  has  been  put  into  that 
watch  than  a  horse  could  exert  at  once.  .  But  suppose 


THE  ULTIMATE  FORCE.  253 

one  had  tried  to  put  all  that  force  into  the  watch  at  once : 
it  would  have  pulverized  it  to  atoms.  But  supposing 
the  universe  had  been  dowered  with  power  at  first  to 
run  its  enormous  rounds  for  twenty  millions  of  years. 
It  is  inconceivable;  steel  would  be  as  friable  as  sand, 
and  strengthless  as  smoke,  in  such  strain. 

We  have  discovered  some  of  the  laws  of  the  force  we 
call  gravitation.  But  what  do  we  know  of  its  essence  ? 
How  it  appears  to  act  we  know  a  little,  what  it  is  we 
are  profoundly  ignorant.  Few  men  ever  discuss  this 
question.  All  theories  are  sublimely  ridiculous,  and  fail 
to  pass  the  most  primary  tests.  How  matter  can  act 
where  it  is  not,  and  on  that  with  which  it  has  no  con- 
nection, is  inconceivable. 

Newton  said  that  any  one  who  has*  in  philosophical 
matters  a  competent  faculty  of  thinking,  could  not  ad- 
mit for  a  moment  the  possibility  of  a  sun  reaching 
through  millions  of  miles,  and  exercising  there  an  at- 
tractive power.  A  watch  may  run  if  wound  up,  but 
how  the  watch-spring  in  one  pocket  can  run  the  watch 
in  another  is  hard  to  see.  A  watch  is  a  contrivance  for 
distributing  a  force  outside  of  itself,  and  if  the  universe 
runs  at  all  on  that  principle,  it  distributes  some  force 
outside  of  itself. 

Le  Sage's  theory  of  gravitation  by  the  infinitive  hail 
of  atoms  cannot  stand  a  minute,  hence  we  come  back  as 
a  necessity  of  thought  to  HerschePs  statement.  "  It  is 
but  reasonable  to  regard  gravity  as  a  result  of  a  con- 
sciousness and  a  will  existent  somewhere."  Where  ?  I 
read  an  old  book  speaking  of  these  matters,  and  it  says 
of  God,  He  hangeth  the  earth  upon  nothing;  he  up- 
holdeth  constantly  all  things  by  the  word  of  his  power. 


254:  THE  ULTIMATE  FORCE. 

By  him.  all  things  consist  or  hold  together.  It  teach- 
es an  imminent  mind ;  an  almighty,  constantly  exerted 
power.  Proof  of  this  starts  up  on  every  side.  There 
is  a  recognized  tendency  in  all  high-class  energy  to  de- 
teriorate to  a  lower  class.  There  is  steam  in  the  boil- 
er, but  it  wastes  without  fuel.  There  is  electricity  in 
the  jar,  but  every  particle  of  air  steals  away  a  little, 
unless  our  conscious  force  is  exerted  to  regather  it. 
There  is  light  in  the  sun,  but  infinite  space  waits  to  re- 
ceive it,  and  takes  it  swift  as  light  can  leap.  We  said 
that  if  the  sun  were  pure  coal,  it  would  burn  out  in  live 
thousand  years,  but  it  blazes  undimmed  by  the  million. 
How  can  it?  There  have  been  various  theories:  chem- 
ical combustion,  it  has  failed ;  meteoric  impact,  it  is 
insufficient ;  condensation,  it  is  not  proved ;  and  if  it 
were,  it  is  an  intermediate  step  back  to  the  original 
cause  of  condensation.  The  far-seeing  eyes  see  in  the 
sun  the  present  active  power  of  Him  who  first  said, 
"Let  there  be  light,"  and  who  at  any  moment  can  meet 
a  Saul  in  the  way  to  Damascus  with  a  light  above  the 
brightness  of  the  sun — another  noon  arisen  on  mid-day  ; 
and  of  whom  it  shall  be  said  in  the  eternal  state  of  un- 
clouded brightness,  where  sun  and  moon  are  no  more, 
"  The  glory  of  the  Lord  shall  lighten  it,  and  the  Lamb 
is  the  light  thereof." 

But  suppose  matter  could  be  dowered,  that  worlds 
could  have  a  gravitation,  one  of  two  things  must  fol- 
low: It  must  have  conscious  knowledge  of  the  position, 
exact  weight,  and  distance  of  every  atom,  mass,  and 
world,  in  order  to  proportion  the  exact  amount  of  grav- 
ity, or  it  must  fill  infinity  with  an  omnipresent  attract- 
ive power,  pulling  in  myriads  of  places  at  nothing ;  in 


THE  ULTIMATE  FORCE.  255 

a  few  places  at  worlds.  Every  world  must  exert  an  in- 
finitely extended  power,  but  myriads  of  infinities  can- 
not be  in  the  same  space.  The  solution  is,  one  infinite 
power  and  conscious  will. 

To  see  the  impossibility  of  every  other  solution,  join  in 
the  long  and  microscopic  hunt  for  the  ultimate  particle, 
the  atom ;  and  if  found,  or  if  not  found,  to  a  consider- 
ation of  its  remarkable  powers.  Bring  telescopes  and 
microscopes,  use  all  strategy,  for  that  atom  is  difficult 
to  catch.  Make  the  first  search  with  the  microscope : 
we  can  count  112,000  lines  ruled  on  a  glass  plate  in- 
side of  an  inch.  But  we  are  here  looking  at  mountain 
ridges  and  valleys,  not  atoms.  Gold  can  be  beaten  to 
the  TTinnnr  °^  au  i°cn-  It  can  t>e  drawn  as  the  coating 
of  a  wire  a  thousand  times  thinner,  to  the  34uuiuuu0  of 
an  inch.  But  the  atoms  are  still  heaped  one  upon  an- 
other. 

Take  some  of  the  infusorial  animals.  Alonzo  Gray 
says  millions  of  them  would  not  equal  in  bulk  a  grain 
of  sand.  Yet  each  of  them  performs  the  functions  of 
respiration,  circulation,  digestion,  and  locomotion.  Some 
of  our  blood-vessels  are  not  a  millionth  of  our  size. 
What  must  be  the  size  of  the  ultimate  particles  that 
freely  move  about  to  nourish  an  animal  whose  totality 
is  too  small  to  estimate?  A  grain  of  musk  gives  off 
atoms  enough  to  scent  every  part  of  the  air  of  a  room. 
You  detect  it  above,  below,  on  every  side.  Then  let 
the  zephyrs  of  summer  and  the  blasts  of  winter  s\veep 
through  that  room  for  forty  years,  bearing  out  into  the 
wide  world  miles  on  miles  of  air,  all  perfumed  from  the 
atoms  of  that  grain  of  musk,  and  at  the  end  of  the  forty 
years  the  weight  of  musk  has  not  appreciably  dimin- 


256  THE   ULTIMATE  FORCE. 

ished.     Yet  uncountable  myriads  on  myriads  of  atoms 
have  gone. 

Our  atom  is  not  found- yet.  Many  are  the  ways  of 
searching  for  it  which  we  cannot  stop  to  consider.  We 
will  pass  in  review  the  properties  with  which  materi- 
alists preposterously  endow  it.  It  is  impenetrable  and 
indivisible.  Atoms  of  arsenic  and  phosphorus  are  one- 
half;  and  of  mercury  and  zinc,  twice  the  normal  size. 
They  have  different  shapes.  They  differ  in  weight,  in 
quantity  of  combining  power,  in  quality  of  combining 
power.  They  combine  with  different  substances,  in  cer- 
tain exact  assignable  quantities.  Thus,  one  atom  of  bro- 
mine combines  with  one  of  hydrogen,  one  of  oxygen  with 
two  of  hydrogen,  one  of  nitrogen  with  three  of  hydrogen, 
one  of  silicon  with  four  of  hydrogen,  etc.  Hence  our 
atom  of  hydrogen  must  have  power  to  count,  or  at  least 
to  measure,  or  be  cognizant  of  bulk.  Again,  atoms  are 
of  different  sorts,  as  positive  or  negative  to  electric 
currents.  They  have  power  to  take  different  shapes 
with  different  atoms  in  crystallization ;  that  is,  there  is 
a  power  in  them,  conscious  or  otherwise,  that  the  same 
bricks  shall  make  themselves  into  stables  or  palaces,  sew- 
ers or  pavements,  according  as  the  mortar  varies.  "No, 
no,"  you  cry  out;  "it  is  only  according  as  the  builder 
varies  his  plan."  There  is  no  need  to  rehearse  these 
powers  much  further;  though  not  one -tenth  of  the 
supposed  innate  properties  of  this  infinitesimal  infinite 
have  been  recited — properties  which  are  expressed  by  the 
words  atomicity,  quantivilence,  monad,  dyad,  univalent, 
perissad,  quadrivalent,  and  twenty  other  terms,  each  ex- 
pressing some  endowment  of  power  in  this  invisible 
atom.  Refer  to  one  more  presumed  ability,  an  ability 


THE  ULTIMATE  FORCE.  257 

to  keep  themselves  in  exact  relation  of  distance  and 
power  to  each  other,  without  touching. 

It  is  well  known  that  water  does  not  fill  the  space  it 
occupies.  We  can  put  eight  or  ten  similar  bulks  of 
different  substances  into  a  glass  of  water  without  great- 
ly increasing  its  bulk,  some  actually  diminishing  it.  A 
philosopher  has  said  that  the  atoms  of  oxygen  and  hy- 
drogen are  probably  not  nearer  to  each  other  in^  water 
than  one  hundred  and  fifty  men  would  be  if  scattered 
over  the  surface  of  England,  one  man  to  four  hundred 
square  miles. 

The  atoms  of  the  luminiferous  ether  are  infinitely 
more  diffused,  and  yet  its  interactive  atoms  can  give 
577  millions  of  millions  of  light-waves  a  second.  And 
now,  more  preposterous  than  all,  each  atom  has  an  at- 
tractive power  for  every  other  atom  of  the  universe. 
The  little  mote,  visible  only  in  a  sunbeam  streaming 
through  a  dark  room,  and  the  atom,  infinitely  smaller, 
has  a  grasp  upon  the  whole  world,  the  far-off  sun,  and 
the  stars  that  people  infinite  space.  The  Sage  of  Con- 
cord advises  you  to  hitch  your  wagon  to  a  star.  But 
this  is  hitching  all  stars  to  an  infinitesimal  part  of  a 
wagon.  Such  an  atom,  so  dowered,  so  infinite,  so  con- 
scious, is  an  impossible  conception. 

But  if  matter  could  be  so  dowered  as  to  produce  such 
results  by  mechanism,  could  it  be  dowered  to  produce 
the  results  of  intelligence?  Could  it  be  dowered  with 
power  of  choice  without  becoming  mind?  If  oxygen 
and  hydrogen  could  be  made  able  to  combine  into  wa- 
ter, could  the  same  unformed  matter  produce  in  one 
case  a  plant,  in  another  a  bird,  in  a  third  a  man ;  and 
in  each  of  these  put  bone,  brain,  blood,  and  nerve  in 


258  THE  ULTIMATE  FORCE. 

proper  relations?  Matter  must  be  mind,  or  subject  to 
a  present  working  mind,  to  do  this.  There  must  be  a 
present  intelligence  directing  the  process,  laying  the 
dead  bricks,  marble,  and  wood  in  an  intelligent  order 
for  a  living  temple.  If  we  do  put  God  behind  a  single 
veil  in  dead  matter,  in  all  living  things  he  must  be  ap- 
parent and  at  work.  If,  then,  such  a  thing  as  an  infi- 
nite atom  is  impossible)  shall  we  not  best  understand 
matter  by  saying/it"  is  a  visible  representation  of  God's 
personal  will  and  power,  of  his  personal  force,  and  per- 
haps knowledge,  set  aside  a  little  from  himself,  still 
possessed  somewhat  of  his  personal  attributes,  still  re- 
sponsive to  his  will/  What  we  call  matter  may  be  best 
understood  as  God's  force,  will,  knowledge,  rendered 
apparent,  static,  and  unweariably  operative.  Unless 
matter  is  eternal,  which  is  unthinkable,  there  was  noth- 
ing out  of  which  the  world  could  be  made,  but  God 
himself ;  and,  reverently  be  it  said,  matter  seems  to  re- 
tain fit  capabilities  for  such  source.  Is  not  this  the 
teaching  of  the  Bible  ?  I  come  to  the  old  Book.  I  come 
to  that  man  who  was  taken  up  into  the  arcana  of  the 
third  heaven,  the  holy  of  holies,  and  heard  things  im- 
possible to  word.  I  find  he  makes  a  clear,  unequivocal 
statement  of  this  truth  as  God's  revelation  to  him. 
"  By  faith,"  says  the  author  of  Hebrews,  "  we  under- 
stand the  worlds  were  framed  by  the  word  of  God,  so 
that,  things  which  are  seen  were  not  made  of  things 
which  do  appear."  In  Corinthians,  Paul  says — But  to 
us  there  is  but  one  God,  the  Father,  of  whom  [as  a 
source]  are  all  things ;  and  one  Lord  Jesus  Christ,  by 
whom  [as  a  creative  worker]  are  all  things.  So  in  Ro- 
mans he  says — "  For  out  of  him,  and  through  him,  and 
ko  him  are  all  things,  to  whom  be  glory  forever.  Amen." 


THE  ULTIMATE  FORCE.  259 

God's  intimate  relation  to  matter  is  explained.  No 
wonder  the  forces  respond  to  his  will ;  no  wonder  pan- 
theism— the  idea  that  matter  is  God — has  had  such  a 
hold  upon  the  minds  of  men.  Matter,  derived  from  him, 
bears  marks  of  its  parentage,  is  sustained  by  him,  and 
when  the  Divine  will  shall  draw  it  nearer  to  himself 
the  new  power  and  capabilities  of  a  new  creation  shall 
appear.  Let  us  pay  a  higher  respect  to  the  attractions 
and  affinities ;  to  the  plan  and  power  of  growth ;  to  the 
wisdom  of  the  ant ;  the  geometry  of  the  bee ;  the  mi- 
grating instinct  that  rises  and  stretches  its  wings  toward 
a  provided  South — for  it  is  all  God's  present  wisdom 
and  power.  Let  us  come  to  that  true  insight  of  the 
old  prophets,  who  are  fittingly  called  seers;  whose  eyes 
pierced  the  veil  of  matter,  and  saw  God  clothing  the 
grass  of  the  field,  feeding  the  sparrows,  giving  snow 
like  wool  and  scattering  hoar-frost  like  ashes,  and  ever 
standing  on  the  bow  of  our  wide -sailing  world,  and 
ever  saying  to  all  tumultuous  forces, "  Peace,  be  still." 
Let  us,  with  more  reverent  step,  walk  the  leafy  soli- 
tudes, and  say : 

"Father,  thy  hand 

Hath  reared  these  venerable  columns.     Thon 
Did'st  weave  this  verdant  roof.     Thou  did'st  look  down 
Upon  the  naked  earth,  and  forthwise  rose 
All  these  fair  ranks  of  trees.     They  in  Thy  sun 
Budded,  and  shook  their  green  leaves  in  Thy  breeze. 

"That  delicate  forest  flower, 
With  scented  breath  and  looks  so  like  a  smile, 
Seems,  as  it  issues  from  the  shapeless  mould, 
An  emanation  of  the  indwelling  life, 
A  visible  token  of  the  unfolding  love 
That  are  the  soul  of  this  wide  universe." — BRYANT. 


260  THE  ULTIMATE  FORGE. 

Philosophy  has  seen  the  vast  machine  of  the  uni- 
verse, wheel  within  wheel,  in  countless  numbers  and 
hopeless  intricacy.  But  it  has  not  had  the  spiritual 
insight  of  Ezekiel  to  see  that  they  were  every  one  of 
them  full  of  eyes — God's  own  emblem  of  the  omni- 
scient supervision. 

What  if  there  are  some  sounds  that  do  not  seem  to  be 
musically  rhythmic.  I  have  seen  where  an  avalanche 
broke  from  the  mountain  side  and  buried  a  hapless 
city;  have  seen  the  face  of  a  cliff  shattered  to  frag- 
ments by  the  weight  of  its  superincumbent  mass,  or 
pierced  by  the  fingers  of  the  frost  and  torn  away.  All 
these  thunder  down  the  valley  and  are  pulverized  to 
sand.  Is  this  music  ?  No,  but  it  is  a  tuning  of  instru- 
ments. The  rootlets  seize  the  sand  and  turn  it  to  soil, 
to  woody  fibre,  leafy  verdure,  blooming  flowers,  and  de- 
licious fruit.  This  asks  life  to  come,  partake,  and  be 
made  strong.  The  grass  gives  itself  to  all  flesh,  the 
insect  grows  to  feed  the  bird,  the  bird  to  nourish  the 
animal,  the  animal  to  develop  the  man. 

Notwithstanding  the  tendency  of  all  high-class  energy 
to  deteriorate,  to  find  equilibrium,  and  so  be  strength- 
less  and  dead,  there  is,  somehow,  in  nature  a  tremen- 
dous push  upward.  Ask  any  philosopher,  and  he  will 
tell  you  that  the  tendency  of  all  endowed  forces  is  to 
find  their  equilibrium  and  be  at  rest  —  that  is,  dead. 
He  draws  a  dismal  picture  of  the  time  when  the  sun 
shall  be  burned  out,  and  the  world  float  like  a  charnel 
ship  through  the  dark,  cold  voids  of  space — the  sun  a 
burned-out  char,  a  dead  cinder,  and  the  world  one  dis- 
mal silence,  cold  beyond  measure,  and  dead  beyond  con- 
sciousness. The  philosopher  has  wailed  a  dirge  with- 


THE  ULTIMATE  FORCE.  261 

out  hope,  a  requiem  without  grandeur,  over  the  world's 
future.  But  nature  herself,  to  all  ears  attuned,  sings 
paeans,  and  shouts  to  men  that  the  highest  energy,  that 
of  life,  does  not  deteriorate. 

Mere  nature  may  deteriorate.  The  endowments  of 
force  must  spend  themselves.  Wound-up  watches  and 
worlds  must  run  down.  But  nature  sustained  by  un- 
expendable  forces  must  abide.  Nature  filled  with  un- 
expendable  forces  continues  in  form.  Nature  impelled 
by  a  magnificent  push  of  life  must  ever  rise. 

Study  her  history  in  the  past.  Sulphurous  realms 
of  deadly  gases  become  solid  worlds;  surplus  sunlight 
becomes  coal,  which  is  reserved  power ;  surplus  carbon 
becomes  diamonds;  sediments  settle  until  the  heavens 
are  azure,  the  air  pure,  the  water  translucent.  If  that  is 
the  progress  of  the  past,  why  should  it  deteriorate  in 
the  future? 

There  is  a  system  of  laws  in  the  universe  in  which 
the  higher  have  mastery  over  the  lower.  Lower  pow- 
ers are  constitutionally  arranged  to  be  overcome ;  high- 
er powers  are  constitutionally  arranged  for  mastery. 
At  one  time  the  water  lies  in  even  layers  near  the 
ocean's  bed,  in  obedience  to  the  law  or  power  of  gravi- 
tation. At  another  time  it  is  heaved  into  mountain 
billows  by  the  shoulders  of  the  wind.  Again  it  flies 
aloft  in  the  rising  mists  of  the  morning,  transfigured 
by  a  thousand  rainbows  by  the  higher  powers  of  the 
sun.  Again  it  develops  the  enormous  force  of  steam 
by  the  power  of  heat.  Again  it  divides  into  two  light 
flying  airs  by  electricity.  Again  it  stands  upright  as 
a  heap  by  the  power  of  some  law  in  the  spirit  realm, 
whose  mode  of  working  we  are  not  yet  large  enough 


262  THE  ULTIMATE  FORCE. 

to  comprehend.  The  \vater  is  solid,  liquid,  gaseous  on 
earth,  and  in  air  according  to  the  grade  of  power  oper- 
ating upon  it. 

The  constant  invention  of  man  finds  higher  and 
higher  powers.  Once  he  throttled  his  game,  and  often 
perished  in  the  desperate  struggle ;  then  he  trapped  it ; 
then  pierced  it  with  the  javelin ;  then  shot  it  with  an 
arrow,  or  set  the  springy  gases  to  hurl  a  rifle-ball  at  it. 
Sometime  he  may  point  at  it  an  electric  spark,  and  it 
shall  be  his.  Once  he  wearily  trudged  his  twenty  miles 
a  day,  then  he  took  the  horse  into  service  and  made 
sixty ;  invoked  the  winds,  and  rode  on  their  steady 
wings  two  hundred  and  forty  ;  tamed  the  steam,  and 
made  almost  one  thousand ;  and  if  he  cannot  yet  send 
his  body,  he  can  his  mind,  one  thousand  miles  a  second. 
It  all  depends  upon  the  grade  of  power  he  uses.  Now, 
hear  the  grand  truth  of  nature :  as  the  years  progress 
the  higher  grades  of  power  increase.  Either  by  discov- 
ery or  creation,  there  are  still  higher  class  forces  to  be 
made  available.  Once  there  was  no  air,  no  usable  elec- 
tricity. There  is  no  lack  of  those  higher  powers  now. 
The  higher  we  go  the  more  of  them  we  find.  Mr. 
Lockyer  says  that  the  past  ten  years  have  been  years  of 
revelation  concerning  the  sun.  A  rnan  could  not  read 
in  ten  years  the  library  of  books  created  in  that  time 
concerning  the  sun.  But  though  we  have  solved  cer- 
tain problems  and  mysteries,  the  mysteries  have  in- 
creased tenfold. 

We  do  not  know  that  any  new  and  higher  forces 
have  been  added  to  matter  since  man's  acquaintance 
with  it.  But  it  would  be  easy  to  add  any  number  of 
them,  or  change  any  lower  into  higher.  That  is  the 


THE  ULTIMATE  FORCE.  263 

meaning  of  the  falling  granite  that  becomes  soil,  of  the 
pulverized  lava  that  decks  the  volcano's  trembling  sides 
with  flowers ;  that  is  the  meaning  of  the  grass  becom- 
ing flesh,  and  of  all  high  forces  constitutionally  ar- 
ranged for  mastery  over  lower.  Take  the  ore  from 
the  mountain.  It  is  loose,  friable,  worthless  in  itself. 
Raise  it  in  capacity  to  cast -ironv  wrought -iron,  steel, 
it  becomes  a  highway  for  the  commerce-  of  nations, 
over  the  mountains  and  under  them.  It  becomes 
bones,  muscles,  body  for  the  inspiring  soul  of  steam. 
It  holds  up  the  airy  bridge  over  the  deep  chasm.  It 
is  obedient  in  your  hand  as  blade,  hammer,  bar,  or 
spring.  It  is  inspirable  by  electricity,  and  bears  hu- 
man hopes,  fears,  and  loves  in  its  own  bosom.  It  has 
been  raised  from  valueless  ore.  Change  it  again  to 
something  as  far  above  steel  as  that  is  above  ore. 
Change  all  earthly  ores  to  highest  possibility;  string 
them  to  finest  tissues,  and  the  new  result  may  fit  God's 
hand  as  tools,  and  thrill  with  his  wisdom  and  creative 
processes,  a  body  fitted  for  God's  spirit  as  well  as  the 
steel  is  fitted  to  your  hand.  From  this  world  take 
opacity,  gravity,  darkness,  bring  in  more  mind,  love, 
and  God,  and  then  we  will  have  heaven.  An  imma- 
nent God  makes  a  plastic  world. 

When  man  shall  have  mastered  the  forces  that  now 
exist,  the  original  Creator  and  Sustainer  will  say,  "Be- 
hold. I  create  all  things  new."  Kature  shall  be  called 

O 

nearer  to  God,  be  more  full  of  his  power.  To  the  long- 
wandering  ^Eneas,  his  divine  mother  sometimes  came 
to  cheer  his  heart  and  to  direct  his  steps.  But  the  god- 
dess only  showed  herself  divine  by  her  departure  ;  only 
when  he  stood  in  desolation  did  the  hero  know  he  had 


264:  THE  ULTIMATE  FORCE. 

stood  face  to  face  with  divine  power,  beauty,  and  love. 
Not  so  the  Christian  scholars,  the  wanderers  in  Nature's 
bowers  to-day.  In  the  first  dawn  of  discovery,  we  see 
her  full  of  beauty  and  strength ;  in  closer  communion, 
we  find  her  full  of  wisdom  ;  to  our  perfect  knowledge, 
she  reveals  an  indwelling  God  in  her ;  to  our  ardent 
love,  she  reveals  an  indwelling  God  in  us. 

But  the  evidence  of  the  progressive  refinements  of 
habitation  is  no  more  clear  than  that  of  progressive  re- 
finement of  the  inhabitant :  there  must  be  some  one  to 
use  these  finer  things.  An  empty  house  is  not  God's 
ideal  nor  man's.  The  child  may  handle  a  toy,  but  a  man 
must  mount  a  locomotive  ;  and  before  there  can  be  New 
Jerusalems  with  golden  streets,  there  must  be  men  more 
avaricious  of  knowledge  than  of  gold,  or  they  would  dig 
them  up ;  more  zealous  for  love  than  jewels,  or  they 
would  unhang  the  pearly  gates.  The  uplifting  refine- 
ment of  the  material  world  has  been  kept  back  until 
there  should  appear  masterful  spirits  able  to  handle  the 
higher  forces.  Doors  have  opened  on  every  side  to  new 
realms  of  power,  when  men  have  been  able  to  wield 
them.  If  men  lose  that  ability  they  close  again,  and 
shut  out  the  knowledge  and  light.  Then  ages,  dark  and 
feeble,  follow. 

Some  explore  prophecy  for  the  date  of  the  grand 
transformation  of  matter  by  the  coming  of  the  Son  of 
Man,  for  a  new  creation.  A  little  study  of  nature  would 
show  that  the  date  cannot  be  fixed.  A  little  study  of 
Peter  would  show  the  same  thing.  He  says,  "What 
manner  of  persons  ought  ye  to  be,  in  all  holy  conversa- 
tion and  godliness,  looking  for  and  hastening  the  com- 
ing of  the  day  of  God,  wherein  the  heavens  being  on 


THE  ULTIMATE  FORCE.  2Gd 

fire  shall  be  dissolved,  and  the  elements  shall  melt  with 
fervent  heat  ?  Nevertheless  we,  -according  t6  his  prom- 
ise, look  for  a  new  heaven  and  a  new  earth." 

The  idea  is,  that  the  grand  transformation  of  matter 
Waits  the  readiness  of  man.  The  kingdom  waits  the 
king.  The  scattered  cantons  of  Italy  were  only  pros- 
trate provinces  till  Victor  Emanuel  came,  then  they 
were  developed  into  united  Italy.  The  prostrate  prov- 
inces of  matter  are  not  developed  until  the  man  is  vic- 
tor, able  to  rule  there  a  realm  equal  to  ten  cities  here. 
Every  good  man  hastens  the  coming  of  the  day  of  God 
and  nature's  renovation.  Not  only  does  inference  teach 
that  there  must  be  finer  men,  but  fact  affirms  that  trans- 
formation has  already  taken  place.  Life  is  meant  to 
have  power  over  chemical  forces.  It  separates  carbon 
from  its  compounds  and  builds  a  tree,  separates  the  ele- 
ments and  builds  the  body,  holds  them  separate  until 
life  withdraws.  More  life  means  higher  being.  Cer- 
tainly men  can  be  refined  and  recapacitated  as  well  as 
ore.  In  Ovid's  "Metamorphoses"  he  represents  the 
lion  in  process  of  formation  from  earth,  hind  quarters 
still  clay,  but  fore  quarters,  head,  erect  mane,  and  blaz- 
ing eye — live  lion — and  pawing  to  get  free.  We  have 
seen  winged  spirits  yet  linked  to  forms  of  clay,  but  beat- 
ing the  celestial  air,  endeavoring  to  be  free;  and  we 
have  seen  them,  dowered  with  new  sight,  filled  with  new 
love,  break  loose  and  rise  to  higher  being. 

In  this  grand  apotheosis  of  man  which  nature  teaches, 
progress  has  already  been  made.  Man  has  already  out- 
grown his  harmony  with  the  environment  of  mere  mat- 
ter. He  has  given  his  hand  to  science,  and  been  lifted 
up  above  the  earth  into  the  voids  of  infinite  space.  He 

12 


266  THE  ULTIMATE  FORCE. 

has  gone  on  and  on,  till  thought,  wearied  amidst  the  in- 
finities of  velocity  and. distance,  has  ceased  to  note  them. 
But  he  is  not  content;  all  his  faculties  are  not  filled. 
He  feels  that  his  future  self  is  in  danger  of  not  being 
satisfied  with  space,  and  worlds,  and  all  mental  delights, 
even  as  his  manhood  fails  to  be  satisfied  with  the  ma- 
teriel toys  of  his  babyhood.  He  asks  for  an  Author  and 
Maker  of  things,  infinitely  above  them.  He  has  seen 
wisdom  unsearchable,  power  illimitable ;  but  he  asks  for 
personal  sympathy  and  love.  Paul  expresses  his  feel- 
ing :  every  creature — not  the  whole  creation — groaneth 
and  travaileth  in  pain  together  until  now,  waiting  for 
the  adoption — the  uplifting  from  orphanage  to  parent- 
age— a  translation  out  of  darkness  into  the  kingdom 
of  God's  dear  Son.  He  hears  that  a  man  in  Christ 
is  a  new  creation  :  old  things  pass  away,  all  things  be- 
come new.  There  is  then  a  possibility  of  finding  the 
Author  of  nature,  and  the  Father  of  man.  He  begins 
his  studies  anew.  Now  he  sees  that  all  lines  of  knowl- 

/edge  converge  as  they  go  out  toward  the  infinite  mys- 
tery ;  sees  that  these  converging  lines  are  the  reins  of 
government  in  this  world ;  sees  the  converging  lines 
grasped  by  an  almighty  hand ;  sees  a  loving  face  and 
form  behind ;  sees  that  these  lines  of  knowledge  and 
power  are  his  personal  nerves,  along  which  flashes  his 
will,  and  every  force  in  the  universe  answers  like  a 
perfect  muscle. 
yThen  he  asks  if  this  Personality  is  as  full  of  love  as 

/of  power.  He  is  told  of  a  tenderness  too  deep  for  tears, 
a  love  that  has  the  Cross  for  its  symbol,  and  a  dying 
cry  for  its  expression :  seeking  it,  he  is  a  new  creation. 
He  sees  more  wondrous  things  in  the  Word  than  in  the 


THE  ULTIMATE  FORCE.  267 

world.  He  comes  to  know  God  with  his  heart,  better 
than  he  knows  God's  works  by  his  mind. 

Every  song  closes  with  the  key-note  with  which  it  be- 
gan, and  the  brief  cadence  at  the  close  hints  the  realms 
of  sound  through  which  it  has  tried  its  wings.  The 
brief  cadence  at  the  close  is  this :  All  force  runs  back 
into  mind  for  its  source,  constant  support,  and  uplifts 
into  higher  grades. 

Mr.  Grove  says,  "  Causation  is  the  will,  creation  is  the 
act,  of  God."  Creation  is  planned  and  inspired  for  the 
attainment  of  constantly  rising  results.  The  order  is 
chaos,  light,  worlds,  vegetable  forms,  animal  life,  then 
man.  There  is  no  reason  to  pause  here.  This  is  not 
perfection,  not  even  perpetuity.  Original  plans  are  not 
accomplished,  nor  original  force  exhausted.  In  another 
world,  free  from  sickness,  sorrow,  pain,  and  death,  per- 
fection of  abode  is  offered.  Perfection  of  inhabitant 
is  necessary;  and  as  the  creative  power  is  everywhere 
present  for  the  various  uplifts  and  refinements  of  mat- 
ter, it  is  everywhere  present  with  appropriate  power 
for  the  uplifting  and  refinement  of  mind  and  spirit. 


SUMMARY   OF  LATEST  DISCOVERIES  AND 
CONCLUSIONS. 

Movements  on  the  Sun. — The  discovery  and  measurement  of 
the  np-rush,  down-rush,  and  whirl  of  currents  about  the  sun- 
spots,  also  of  the  determination  of  the  velocity  of  rotation  by 
means  of  the  spectroscope,  as  described  (page  53),  is  one  of  the 
most  delicate  and  difficult  achievements  of  modern  science. 

Movement  of  Stars  in  Line  of  Sight  (page  51). — The  fol- 
lowing table  shows  this  movement  of  stars,  so  far  as  at  present 
known : 


APPROACHING. 

RKORDING. 

Map. 

Name. 

Rate 
per  sec. 

Map. 

Name. 

Kate 
per  sec. 

Fig.  71 

Arctnrus  

55  miles 

Fig.  69 

Sirius  

20  miles 

"     72 

Vega 

50     " 

Fr'piece 

Betelguese 

22     " 

"     73 
"     69 

a  Cvgui  
Pollux 

39     " 
49     " 

n 
Fig   69 

Kigel  
Ouster 

15     " 

25     " 

"    67 

Dubhe  

46     " 

"     70 

lie^ulns 

15     " 

Sun's  Appearance. — This  was  formerly  supposed  to  be  an 
even,  regular,  dazzling  brightness,  except  where  the  spots  ap- 
peared. But  the  sun's  surface  is  now  known  to  be  mottled 
with  what  are  called  rice  grains  or  willow  leaves.  But  the 
rice  grains  are  as  large  as  the  continent  of  America.  The 
spaces  between  are  called  pores.  They  constitute  an  innumer- 
able number  of  small  spots.  This  appearance  of  the  general 
surface  is  well  portrayed  in  the  cut  on  page  92. 

Close  Relation  betiveen  Sun  and  Earth. — Men  always  knew 
that  the  earth  received  light  from  the  sun.  They  subsequently 
discovered  that  the  earth  was  momentarily  held  by  the  power 


SUMMARY  OF  LATEST  DISCOVERIES,  ETC.       269 

of  gravitation.  But  it  is  a  recent  discovery  that  the  light  is 
one  of  the  principal  agents  in  chemical  changes,  in  molecular 
grouping  and  world -building,  thus  making  all  kinds  of  life 
possible  (p.  30-36).  The  close  connection  of  the  sun  and 
the  earth  will  be  still  farther  shown  in  the  relation  of  sun-spots 
and  auroras.  One  of  the  most  significant  instances  is  related 
on  page  19,  when  the  earth  felt  the  fall  of  bolides  upon  the 
sun.  Members  of  the  body.no  more  answer  to  the  heart  than 
the  planets  do  to  the  sun. 

Hydrogen  Flames. — It  has  been  demonstrated  that  the  sun 
flames  200,000  miles  high  are  hydrogen  in  a  state  of  flaming 
incandescence  (page  85). 

Sun's  Distance. — The  former  estimate,  95,513,794  miles,  has 
been  reduced  by  nearly  one-thirtieth.  Lockyer  has  stated  it  as 
low  as  89,895,000  miles,  and  Proctor,  in  "  Encyclopedia  Bri- 
tannica,"  at  91,430,000  miles,  but  discovered  errors  show  that 
these  estimates  are  too  small.  Newcomb  gives  92,400,000  as 
within  200,000  miles  of  the  correct  distance.  The  data  for  a 
new  determination  of  this  distance,  obtained  from  the  transit 
of  Venus,  December  8th,  1874,  have  not  yet  been  deciphered; 
a  fact  that  shows  the  difficulty  and  laboriousness  of  the  work. 
Meanwhile  it  begins  to  be  evident  that  observations  of  the 
transit  of  Venus  do  not  afford  the  best  basis  for  the  most  per- 
fect determination  of  the  sun's  distance. 

Since  the  earth's  distance  is  our  astronomical  unit  of  meas- 
ure, it  follows  that  all  other  distances  will  be  changed,  when 
expressed  in  miles,  by  this  ascertained  change  of  the  value  of 
the  standard. 

Oxygen  in  the  Sun. — In  1877  Professor  Draper  announced 
the  discover)7  of  oxygen  lines  in  the  spectrum  of  the  sun.  The 
discovery  was  doubted,  and  the  methods  used  were  criticised  by 
Lockyer  and  others,  but  later  and  more  delicate  experiments 
substantiate  Professor  Draper's  claim  to  the  discovery.  The 
elements  known  to  exist  in  the  sun  are  salt,  iron,  hydrogen, 


270       SUMMARY  OF  LATEST  DISCOVERIES,  ETC. 

magnesium,  barium,  copper,  zinc,  cromium,  and  nickel.  Some 
elements  in  the  sun  are  scarcely,  if  at  all,  discoverable  on  the 
earth,  and  some  on  the  earth  not  yet  discernible  in  the  sun. 

Substance  of  Stars. — Aldebaran  (Frontispiece)  shows  salt, 
magnesium,  hydrogen,  calcium,  iron,  bismuth,  tellurium,  anti- 
mony, and  mercury.  Some  of  the  sun's  metals  do  not  appear. 
Stars  differ  in  their  very  substance,  and  will,  no  doubt,  introduce 
new  elements  to  us  unknown  before. 

The  theory  that  all  nebulaB  are  very  distant  clusters  of  stars 
is  utterly  disproved  by  the  clearest  proof  that  some  of  them  are 
only  incandescent  gases  of  one  or  two  kinds. 

Discoveries  of  New  Bodies. — The  four  planetoids  nearest  the 
sun  (page  138).  The  two  satellites  of  Mars  were  discovered  by 
Mr.  Hall,  IT.  S.  Naval  Observatory,  August  llth,  1877  (page 
161).  The  outer  one  is  called  Dicmas;  the  inner,  Phobus. 

Sir  William  Herschel  thought  he  discovered  six  satellites  of 
Uranus.  The  existence  of  four  of  them  has  been  disproved  by 
the  researches  of  men  with  larger  telescopes.  Two  new  ones, 
however,  were  discovered  by  Mr.  Lassell  in  1846. 

Saturn's  Rings  are  proved  to  be  in  a  state  of  fluidity  and 
contraction  (page  171). 

Meteors  and  Comets.  —  The  orbits  of  over  one  hundred 
swarms  of  meteoric  bodies  are  fixed :  their  relation  to,  and  in 
some  cases  indentity  with,  comets  determined.  Some  comets 
are  proved  to  be  masses  of  great  weight  and  solidity  (page  133). 

Aerolites.  —  Some  have  a  texture  like  our  lowest  strata  of 
rocks.  There  is  a  geology  of  stars  and  meteors  as  well  as  of 
the  earth.  M.  Meunier  has  just  received  the  Lalande  Medal 
from  the  Paris  Academy  for  his  treatise  showing  that,  so  far  as 
our  present  knowledge  can  determine,  some  of  these  meteors 
once  belonged  to  a  globe  developed  in  true  geological  epochs, 
and  which  has  been  separated  into  fragments  by  agencies  with 
which  we  are  not  acquainted. 

Dr.  O.  Hahn,  a  German  lawyer,  proves   the   existence  of 


SUMMARY  OF  LATEST  DISCOVERIES,  ETC.       271 

organic  remains  in  the  stones  that  come  from  space.  From 
museums  in  Tubingen  and  in  Vienna  Hahn  procured  himself 
more  than  six  hundred  chips  of  meteorites  of  the  Choadrite 
class,  proved  in  each  case  to  be  genuine,  and  having  been  col- 
lected on  eighteen  different  occasions,  partly  during  the  pres- 
ent and  partly  during  the  last  century,  in  Europe,  Asia,  and 
America.  Minute  inspection  has  discovered  in  them  a  quan- 
tity of  organic  remains,  principally  belonging  to  the  most 
ancient  form  of  porous  corallines,  to  the  genus  of  fossil  zoo- 
phytes denominated  Favosites,  or  at  least  bearing  a  very 
strong  resemblance  to  these  latter,  though  of  a  still  smaller 
type.  About  fifty  kinds  of  these  tiny  animals  have  been  made 
out  by  Dr.  Hahn,  and  assigned  to  sixteen  different  families. 

Dr.  D.  F.  Weinland,  who  has  devoted  a  year  to  the  study  of 
Hahn's  book,  and  testing  his  microscopic  researches,  says  that 
it  is  only  the  shell  of  the  Choadrite  meteorite  that  is  burnt 
and  glazed  by  friction  with  our  atmosphere.  The  heat  does 
not  extend  so  far  during  the  short  transit  of  the  meteor  as  to 
impair  the  kernel,  which  has  an  appearance  somewhat  like 
coarse  shell  lime,  of  a  conglomeration  of  petrified  organic  mat- 
ter, baked  in  a  lump.  Though  only  few  specimens  can  be 
called  well  preserved,  yet  the  substance  is  sufficiently  distin- 
guishable to  enable  us  to  class  most  of  the  structures  among 
the  Polycistines  and  the  Foramimfera.  They  must  have  ex- 
isted in  water  warm  enough  never  to  freeze  down  to  the 
bottom.  Where  are  we  to  seek  for  this  water,  if  Professor 
Schiaparelli  tells  us  that  meteorites  do  not  belong  to  our  solar 
system,  but  are  intruders  from  without?  Very  strange  is  the 
complete  resemblance  of  all  the  cuttings  examined  to  one  an- 
other, though,  as  stated,  they  belong  to  stones  fallen  at  dif- 
ferent periods  in  all  parts  of  the  globe.  Are  these  parts  of 
an  exploded  world,  or  have  these  little  worlds  developed  life 
in  a  manner  similar  to  larger  ones? 

The  Horizontal  Pendulum. — This  delicate  instrument  is  rep- 


272       SUMMARY  OF  LATEST  DISCOVERIES,  ETC. 


resented  in  Fig.  82.  It  consists  of  an  upright  standard,  strongly 
braced ;  a  weight,  m,  suspended  by  the  hair-spring  of  a  watch, 
B  D,  and  held  in  a  horizontal  position  by  another  watch-spring, 
A  C.  The  weight  is  deflected  from  side  to  side  by  the  slight- 
est influence.  The  least  change  in  the  level  of  a  base  thirty- 
nine  inches  long  that  could  be  detected  by  a  spirit-level  is  0".l 
of  an  arc — equal  to  raising  one  end  oirW  °f  an  inch.  But  the 
pendulum  detects  a  raising  of  one 
end  Tjnnnunnr  of  an  inch.  To  ob- 
serve the  movements  of  the  pendu- 
lum, it  is  kept  in  a  dark  room,  and  a 
ray  of  light  is  directed  to  the  mirror, 
m,  and  thence  reflected  upon  a  screen. 
Thus  the  least  movement  may  be  enor- 
mously magnified,  and  read  and  meas- 
ured by  the  moving  spot  on  the  screen. 
It  has  been  discovered  that  when  the 
sun  rises  it  has  sufficient  attraction  to 
incline  this  instrument  to  the  east ; 
when  it  sets,  to  incline  it  to  the  west. 
The  same  is  true  of  the  moon.  When 
cither  is  exactly  overhead  or  under- 
foot, of  course  there  is  no  deflection. 
The  mean  deflection  caused  by  the 
moon  at  rising  or  setting  is  0".0l74; 
by  the  sun,  0".008.  Great  results  are 
expected  from  this  instrument  hardly 
known  as  yet :  among  others,  whether 

Fig. S2.-Horizoutal  Pendulum.    gravitation  actg  instailtly  or  Consumes 

time  in  coming  from  the  sun.  This  will  be  shown  by  the  time 
of  the  change  of  the  pendulum  from  east  to  west  when  the  sun 
reaches  the  zenith,  and  vice  versa  when  it  crosses  the  nadir.  The 
sun  will  be  best  studied  without  light,  in  the  quiet  and  darkness 
of  some  deep  mine. 


SUMMAR  Y  OF  LA  TEST  DISCO  VERIES,  ETC.        273 

Light  of  Unseen  Stars.  —  From  careful  examination,  it  ap- 
pears that  three-fourths  of  the  light  on  a  fine  starlight  night 
comes  from  stars  that  cannot  be  discerned  by  the  naked  eye. 
The  whole  amount  of  star  light  is  about  one-eightieth  of  that 
of  the  full  moon. 

Lateral  Movements  of  Stars,  page  226-28. 

Future  Discoveries — A  Trans-Neptunian  Planet. — Professor 
Asaph  Hall  says :  "  It  is  known  to  me  that  at  least  two  Amer- 
ican astronomers,  armed  with  powerful  telescopes,  have  been 
searching  quite  recently  for  a  trans-Neptunian  planet.  These 
searches  have  been  caused  by  the  fact  that  Professor  New- 
comb's  tables  of  Uranus  and  Neptune  already  begin  to  differ 
from  observation.  But  are  we  to  infer  from  these  errors  of 
the  planetary  tables  the  existence  of  a  trans-Neptunian  planet  ? 
It  is  possible  that  such  a  planet  may  exist,  but  the  probability 
is,  I  think,  that  the  differences  are  caused  by  errors  in  the  theo- 
ries of  these  planets.  *  *  *  A  few  years  ago  the  remark  was  fre- 
quently made  that  the  labors  of  astronomers  on  the  solar  system 
were  finished,  and  that  henceforth  they  could  turn  their  whole 
attention  to  sidereal  astronomy.  But  to-day  we  have  the  lunar 
theory  in  a  very  discouraging  condition,  and  the  theories  of 
Mercury,  Jupiter,  Saturn,  Uranus,  and  Neptune  all  in  need  of 
revision  ;  unless,  indeed,  Leverrier's  theories  of  the  last  two  plan- 
ets shall  stand  the  test  of  observation.  But,  after  all,  such  a 
condition  of  things  is  only  the  natural  result  of  long  and  accu- 
rate series  of  observations,  which  make  evident  the  small  inequal- 
ities in  the  motions,  and  bring  to  light  the  errors  of  theory." 

Future  discoveries  will  mostly  reveal  the  laws  and  conditions 
of  the  higher  and  finer  forces.  Already  Professor  Loom  is  tele- 
graphs twenty  miles  without  wire,  by  the  electric  currents  be- 
tween mountains.  We  begin  to  use  electricity  for  light,  and 
feel  after  it  for  a  motor.  Comets  and  Auroras  show  its  pres- 
ence between  worlds,  and  in  the  interstellar  spaces.  Let  an- 
other Newton  arise. 

12* 


274 


ELEMENTS   OF  TEE  SOLAR  SYSTEM. 


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CO 

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Masses. 

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ASTRONOMICAL  SYMBOLS. 


275 


EXPLANATION  OF  ASTRONOMICAL  SYMBOLS. 

SIGNS  OP  THE  ZODIAC. 


0.  T   Aries 0° 

1.  8    Taurus 30 

II.  n   Gemini 60 

III.  ©  Cancer 90 

IV.  ft  Leo ..120 

V.  TT£  Virgo 150 


VI.  =£=  Libra 180° 

VII.   TTi  Scorpio 210 

VIII.    £    Sagittarius 240 

IX.  V3  Capricornus 270 

X.  ffff  Aquarius 300 

XL   X  Pisces 330 


c$  Conjunction. 

[J  Quadrature. 

8  Opposition. 

£3  Ascending  Node. 

£3  Descending  Node. 

H.  Hours. 

M.  Minutes  of  Time. 


S.  Seconds  of  Time. 

0  Degrees. 

'  Minutes  of  Arc. 

"  Seconds  of  Arc. 

R.  A.  Right  Ascension. 

Decl.  or  I).  Declination. 

N.  P.  D.  Dist.  from  North  Pole. 


OTHER  ABBREVIATIONS  USED  IN  THE  ALMANAC. 

S.,  south,  i.e.,  crosses  the  meridian;  M.,  morning;  A,  afternoon; 
Gr.  H.  L.  N.,  greatest  heliocentric  latitude  north,  i.e.,  greatest  distance 
north  of  the  ecliptic,  as  seen  from  the  sun.  &  $  O  Inf.,  inferior  con- 
junction ;  Sup.,  superior  conjunction. 


GREEK  ALPHABET  USED  INDICATING  THE  STARS. 


a,  alpha. 

»/,  eta. 

v,  nu. 

T,  tau. 

|3,  beta. 

9,  theta. 

5,  xi. 

v,  upsilon. 

y,  gamma. 

t,  iota. 

o,  omicron. 

0,  phi. 

d,  delta. 

K,  kappa. 

IT,  pi. 

X.  chi- 

e,  epsilon. 

X,  lambda. 

p,  rho. 

^,  psi. 

£,  zeta. 

/i,  mu. 

<r,  sigma. 

w,  omega. 

CHAUTAUQUA  OUTLINE  FOR  STUDENTS. 

As  an  aid  to  comprehension,  every  student  should  draw  illus- 
trative figures  of  the  various  circles,  planes,  and  situations  de- 
scribed. (For  example,  see  Fig.  45,  page  112.)  As  an  aid  to 
memory,  the  portion  of  this  outline  referring  to  each  chapter 
should  be  examined  at  the  close  of  the  reading,  and  this  mere 
sketch  filled  up  to  a  perfect  picture  from  recollection. 

I.  Creative  Processes. — The  dial-plate  of  the  sky.     Cause  of  different 
weights — on  sun,  moon.     Two  laws  of  gravity.     Inertia.     Fall  of  earth 
to  sun  per  second.     Forward  motion.     Elastic  attraction.     Perturbation 
of  moon  ;  of  Jupiter  and  Saturn.     Oscillations  of  planets. 

II.  Light. — From  condensation.     Number  of  vibrations  of  red  ;  violet. 
Thermometer  against  air.     Aerolite  against  earth.     Two  bolides  against 
the  sun.     Large  eye.     Velocity  of  light.     Prism.     Color  means  different 
vibrations.     Music  of  light.     Light  reports  substance  of  stars.    Force  of ; 
bridge,  rain,  dispersion,  intensities,  reflection,  refraction,  decomposition. 

III.  Astronomical   Instruments. — Refracting    telescope.      Reflecting-; 
largest.     Spectroscope.     Spectra  of  sun,  hydrogen,  sodium,  etc.    E  made 
G  by  approach  ;  C  by  departure.     Stars  approach  and  recede. 

IV.  Celestial  Measurements. — Place  and  time  by  stars.    Degrees,  min- 
utes, seconds.      Mapping  stars.      Mural  circle.      Slow  watch.      Hoosac 
Tunnel.     Fine  measurements.     Sidereal  time.     Spider -lines.     Personal 
equation.     Measure  distance — height.     Ten-inch  base  line.     Parallax  of 
sun,  stars.    Longitude  at  sea.    Distance  of  Polaris,  a  Centauri,  61  Cygni. 
Orbits  of  asteroids. 

V.  The  Sun. — World  on  fire.     Apparent  size  from  planets.     Zodiacal 
light.      Corona.      Hydrogen  —  how  high?     Size.      How  many  earths? 
Spots :    1.  Motion  ;   2.  Edges ;   3.  Variable ;   4.  Periodic ;    5.  Cyclonic ; 
6.  Size  ;   7.  Velocities.     What  the  sun  does.     Experiments. 

VI.  The  Planets  from  Space. — North  Pole.      Speed.      Sizes.     Axial 
revolution.    Man's  weight  on.    Seasons.    Parallelism,  of  axis.    Earth  near 


CHAUTAUQUA  OUTLINE  FOR  STUDENTS.         277 

sun  in  winter.  Plane  of  ecliptic.  Orbits  inclined  to.  Earth  rotates. 
Proof.  Sun's  path  among  stars.  Position  of  planets.  Motion — direct, 
retrograde.  Experiments. 

VII.  Meteors. — Size;  number;  cause  of;  above  earth ;  velocity;  col- 
ors; number  in  space  ;  telescopic  view  of.     Aerolites:  Systems  of;  how 
many  known.     Comets:  Orbits;  number  of  comets;  llalley's  ;  Biela's 
lost ;  Encke's.     Resisting  medium.     Whence  come  comets  ?     Composed 
of  what  ?     Amount  of  matter  in.     0 . 

VIII.  The  Planets. — How  many  ?  Uranus  discovered  ?  Neptnne?  As- 
teroids ?    Vulcan  ?     Distance  from  sun.     Periodic  time.     Mercury  :  Ele- 
ments ;  shapes,  as  seen  from  earth  ;  transits.    Venus  :  Elements ;  seen  by 
day  ;   how  near  earth  ?   how  far  from  ?   phases ;   Galileo.      Earth  :   Ele- 
ments ;   in  space ;   Aurora ;   balance  of  forces.     Tides :    Main  and  sub- 
sidiary causes  ;  eastern  shores  ;  Mediterranean  Sea.     Moon  :  Elements ; 
hoax ;   moves  east ;   see  one  side ;   three  causes  help  to  see  more  than 
half.     Revolution:  Why  twenty-nine  and  a  half  days :  heat — cold;  how 
much  light?     Craters  and  peaks  lighted;    measured.     Eclipses  —  Why 
not  every  new  and  full  moon  ?     Periodicity.      Mars :    Elements ;   how 
near  earth?      How  far  from?      Apparent  size;   ice-fields;   which  end 
most?     Satellites — Asteroids :  How  found  ?    When?    By  whom?    How 
many?     Jupiter:    Elements;   trade  -  winds ;    how  much   light  received? 
Own  heat.     Satellites  :  How  many  ?    Colors.     Saturn :  Elements ;  habi- 
tability;  rings;  flux;    satellites.     Uranus:   Elements;   discoverer;   seen 
by  ;   moon's  motion.     Neptune :    Elements ;   discovered  by ;  how  ?     Re- 
view system. 

IX.  The  Nebular  Hypothesis. — State  it ;    facts  confirmatory.     Objec- 
tions— 1.  Heat;  2.  Rotation;  3.  Retrograde;  4.  Martial  moons ;  5.  Star 
of  1876.     Evolution  :  Gaps  in  ;  conclusion. 

X.  The  Stellar  System. — Motto.     Man  among  stars  ;  open  page ;  starry 
poem  ;   stars   located ;  named.    Thuban.     Etanin.  Constellations :  Know 
them  ;    number  of  stars  ;    double ;    e  Lyras,  Sirius,  Procyon,  Castor,  61 
Q"8m>  7  Virginis.     Colored  stars ;  change  color.     Clust  jrs  :  Two  theo- 
ries.    Nebulae:  Two  visible;  composed  of;   shapes;    where?     Variable 
stars.    Sun.    /3  Lyra?,  Mira,  Betelguese,  Algol ;  cause.    Temporary ;  1572. 
New  star  of  1866  :  Two  theories.     Star  of  1876.     Movements  of  stars  ; 
Sirius;  sun;  1830  Groombridge.     Stars  near  Pleiades :  Orion,  Great  Dip- 
per, Southern  Cross.     Centre  of  gravity. 

XI.  The  Worlds  and  the  Word. — Rich.    Number.    Erroneous  allusions. 
Truth  before  discovery  :  1.  A  beginning;  2.  Creation  before  arrangement; 
3.  Light  before  sun  ;  4.  Mountains  under  water;  5.  Order  of  development ; 


278         CHAUTAUQUA   OUTLINE  FOR  STUDENTS. 

6.  Sphere  of  earth  ;  7.  How  upheld ;  8.  Number  of  stars  ;  9.  Weight  of 
air;  10.  Meteorology;  11.  Queries  to  Job;  12.  Sun  to  end  of  heaven; 
13.  View  of  Mitchell ;  14.  Herschel.  What  is  matter  ?  Force?  End  of 
earth.  Way  to  knowledge.  Work  of  light.  Transfiguration  of  matter. 
Uniformitarianism.  A  whisper  of  Him.  Man  for  mastery.  Each  a  type 
of  higher.  Survival  of  fittest.  Uranus.  Worlds  and  Word  one  language. 
XII.  The  Ultimate  Force. — Universe  shows  power :  1.  Rain;  Niagara; 
2.  Vegetable  growth  ;  3.  Worlds  carried  ;  4.  Sun  ;  fill  dome  with  worlds ; 
5.  Double  suns ;  6.  Galaxies.  Correlation.  What  ultimate  ?  Mind  and 
will.  What  continuous  relation  ?  Watch.  Theories  of  gravitation : 
Newton's,  Le  Sage's,  Bible's.  High -class  energy  deteriorates.  Search 
for  atoms :  1.  Microscope ;  2.  Gold ;  3.  Infusoria ;  4.  Musk.  Proper- 
ties of  atoms :  1.  Impenetrable ;  2.  Indivisible ;  3.  Shape ;  4.  Quality ; 
5.  Crystallization ;  6.  Not  touch  each  other :  7.  Active ;  8.  Attractive ; 
9.  Intelligent.  Whose?  Relation  of  matter  to  God;  rock  to  soil. 
Push  upward.  Highest  has  mastery.  Man  advances  by  highest.  Mat- 
ter incapacitated.  Refined  habitations.  Inhabitants.  All  force  leads 
back  to  mind.  Personal  and  infinite. 


GLOSSAEY  OF  ASTBONOMICAL  TEEMS 
AND  INDEX. 

Abbreviations  used  in  astronomies,  275. 

Aberration  of  light  (a  wandering  aicay),  an  apparent  displace- 
ment of  a  star,  owing  to  the  progressive  motion  of  light  com- 
bined with  that  of  the  earth  iu  its  orbit,  199. 

Aerolite  (air-stone),  122. 

Air,  refraction  of  the,  40. 

Algol,  the  variable  star,  222. 

Almanac,  Nautical,  71 ;  explanation  of  signs  used,  275. 

Alphabet,  Greek,  275. 

Altitude,  angular  elevation  of  a  body  above  the  horizon. 

Angle,  difference  iu  directions  of  two  straight  lines  that  meet. 

Annular  (ring-shaped)  eclipses,  158  ;  nebulae,  218,  220. 

Aphelion,  the  point  in  an  orbit  farthest  from  the  sun. 

Apogee,  the  point  of  an  orbit  which  is  farthest  from  the  earth. 

Apsis,  plural  apsides,  the  line  joining  the  aphelion  and  perihelion 
points ;  or  the  major  axis  of  elliptical  orbits. 

Arc,  a  part  of  a  circle. 

Ascension,  right,  the  angular  distance  of  a  heavenly  body  from 
the  first  point  of  Aries,  measured  on  the  equator. 

Asteroids  (star-like),  162 ;  orbits  of  interlaced,  74. 

Astronomical  instruments,  43. 

Astronomy,  use  of,  57. 

Atom,  size  of,  255 ;  power  of,  256. 

Aurora  Borealis,  143. 

Axis,  the  line  about  which  a  body  rotates. 

Azimuth,  the  angular  distance  of  any  point  or  body  in  the  horizon 
from  the  north  or  south  points. 

Bailey's  beads,  dots  of  light  on  the  edge  of  the  moon  seen  in  a  so- 
lar eclipse,  caused  by  the  moon's  inequalities  of  surface. 

Base  line,  68. 

Biela's  comet,  129. 

Binary  system,  a  double  star,  the  component  parts  of  which  re- 
volve around  their  centre  of  gravity. 

Bode's  law  of  planetary  distances  is  no  law  at  all,  but  a  study  of 
coincidences. 

Bolides,  small  masses  of  matter  in  space.  They  are  usually  called 
meteors  when  luminous  by  contact  with  air,  120. 


280  GLOSSARY  AND  INDEX. 

Celestial  sphere,  the  apparent  dome  iu  which  the  heavenly  hodies 
seein  to  be  set ;  appears  to  revolve,  3. 

Centre  of  gravity,  the  point  on  which  a  body,  or  two  or  more  re- 
lated bodies,  balances. 

Centrifugal  force  (centre  fleeing'). 

Chromolithic  plate  of  spectra  of  metals,  to  face  50. 

Circumpolar  stars,  map  of  north,  201. 

Colors  of  stars,  214. 

Colures,  the  four  principal  meridians  of  the  celestial  sphere  pass- 
ing from  the  pole,  one  through  each  equiuox,  and  one  through 
each  solstice. 

Comets,  126 ;  Halley's,  128 ;  Biela's  lost,  129 ;  Encke's,  130 ;  consti- 
tution of,  131 ;  will  they  strike  the  earth  ?  133. 

Conjunction.  Two  or  more  bodies  are  in  conjunction  when  they 
are  in  a  straight  line  (disregarding  inclination  of  orbit)  with  the 
sun.  Planets  nearer  the  sun  than  the  earth  are  in  inferior  con- 
junction when  they  are  between  the  earth  and  the  sun;  superior 
conjunction  when  they  are  beyond  the  sun. 

Constellation,  a  group  of  stars  supposed  to  represent  some  figure : 
circumpolar,  201 ;  equatorial,  for  December,  202 ;  for  January,  203 ; 
April,  204;  June,  205;  September,  206 ;  November,  207 ;  southern 
circumpolar,  208. 

Culmination,  the  passage  of  a  heavenly  body  across  the  meridian 
or  south  point  of  a  place ;  it  is  the  highest  point  reached  in  its 
path. 

Cusp,  the  extremities  of  the  crescent  form  of  the  moon  or  an  inte- 
rior planet. 

Declination,  the  angular  distance  of  a  celestial  body  north  or  south 
from  the  celestial  equator. 

Degree,  the  1S^S  part  of  a  circle. 

Direct  motion,  a  motion  from  west  to  east  among  stars. 

Disk,  the  visible  surface  of  sun,  moon,  or  planets. 

Distance  of  stars,  70. 

Double  stars,  210. 

Earth,  revolution  of,  109 ;  in  space,  142 ;  irregular  figure,  145. 

Eccentricity  of  an  ellipse,  the  distance  of  either  focus  from  centre. 
A  planet's  orbit  has  comparatively  little,  a  comet's  very  much. 

Eclipse  (a  disappearance},  157. 

Ecliptic,  the  apparent  annual  path  of  the  sun  among  the  stars ; 
plane  of,  106. 

Egress,  the  passing  of  one  body  off  the  disk  of  another. 

Elements,  the  quantities  which  determine  the  motion  of  a  planet : 
data  for  predicting  astronomical  phenomena;  table  of  solar,  274. 

Elements,  chemical,  present  in  the  sun,  270. 

Elongation,  the  angular  distance  of  a  planet  from  the  sun. 

Emersion,  the  reappearance  of  a  body  after  it  has  been  eclipsed  or 
occulted  by  another. 


GLOSSARY  AND  INDEX.  281 

Equator,  terrestrial,  the  great  circle  half-way  between  the  poles  of 
the  earth.  When  the  plane  of  this  is  extended  to  the  heavens, 
the  line  of  contact  is  called  the  celestial  equator. 

Equinox,  either  of  the  points  in  which  the  sun,  in  its  apparent  an- 
nual course  among  the  stars,  crosses  the  equator,  making  days 
and  nights  of  equal  length. 

Evolution,  materialistic,  182 ;  insufficient,  189. 

Fizeau  determines  the  velocity  of  light,  23. 

Forces,  delicate  balance  of,  144. 

Galileo,  construction  of  his  telescope,  43. 

Geocentric,  a  position  of  a  heavenly  body  as  seen  or  measured  from 
the  earth's  centre. 

Geodesy,  the  art  of  measuring  the  earth  without  reference  to  the 
heavenly  bodies. 

God,  relation  of,  to  the  universe,  258. 

Gravitation,  laws  of,  6 ;  extends  to  the  stars,  13 ;  theories  of,  253. 

Gravity  on  different  bodies,  6,  274. 

Helical,  rising  or  setting  of  a  star,  as  near  to  sunrise  or  sunset  as  it 
can  be  seen. 

Heliocentric,  as  seen  from  the  centre  of  the  sun. 

Hoosac  Tunnel,  example  of  accuracy,  62. 

Horizontal  pendulum,  272. 

Immersion,  the  disappearance  of  one  body  behind  another,  or  in 
its  shadow. 

Inclination  of  an  orbit,  the  angle  between  its  plane  and  the  piano 
of  the  ecliptic. 

Inferior  conjunction,  when  an  interior  planet  is  between  the  earth 
and  the  sun. 

Jupiter,  apparent  path  of,  in  1866, 112  ;  elements  of,  164  ;  satellites 
of,  165;  positions  of  satellites,  166 ;  elements  of  satellites,  166; 
the  Jovian  system,  167. 

Kepler's  Laws— 1st,  that  the  orbits  of  planets  are  ellipses,  having 
the  sun  or  central  body  in  one  of  the  foci ;  2d,  the  radius-vector 
passes  over  equal  spaces  in  equal  times;  3d,  the  squares  of  the 
periodic  times  of  the  planets  are  in  proportion  to  the  cubes  of 
their  mean  distances  from  the  sun. 

Latitude,  the  angular  distance  of  a  heavenly  body  from  the  ecliptic. 

Light,  the  child  of  force,  17 ;  number  of  vibrations  of,  18, 25 ;  veloc- 
ity of,  22 ;  undulatory  and  musical,  26 ;  chemical  force  of,  30 ;  ex- 
periments with,  37 ;  approach  and  departure  of  a  light-giving 
body  measured,  51 ;  aberration  of,  199. 

Limb,  the  edge  of  the  disk  of  the  moon,  sun,  or  a  planet. 

Longitude.  If  a  perpendicular  be  dropped  from  a  body  to  the 
ecliptic,  its  celestial  longitude  is  the  distance  of  the  foot  of  tho 
perpendicular  from  the  vernal  equinox,  counted  to  ward  the  east; 
mode  of  ascertaining  terrestrial,  72. 

Magellanic  clouds,  208. 


282  GLOSSARY  AND  INDEX. 

Mars,  159 ;  snow  spots  of,  160 ;  satellites  of,  161. 

Mass,  the  quantity  of  matter  a  body  contains. 

Mean  distance  of  a  planet,  half  the  sum  of  the  aphelion  and  peri- 
helion distances. 

Measurements,  celestial,  57. 

Mercury,  138. 

Meridian,  terrestrial,  of  a  place,  a  great  circle  of  the  heavens  pass- 
ing through  the  poles,  the  zenith,  and  the  north  and  south  points 
of  the  horizon  ;  celestial,  any  great  circle  passing  from  one  pole 
to  the  other. 

Meteors,  119;  swarm  of,  meeting  the  earth,  118;  explosion  of,  120; 
systems  of,  123  ;  relation  of,  to  comets,  124. 

Micrometer,  any  instrument  for  the  accurate  measurement  of  very 
small  distances  or  angles. 

Mind,  origin  of  force,  252 ;  continuous  relation  of,  to  the  universe, 
252. 

Milky  Way,  210,  215. 

Mira,  the  Wonderful,  221. 

Moon,  the,  151 ;  greatest  and  least  distance  from  the  earth,  10 ;  tele- 
scopic appearance  of,  155. 

Mural  circle,  61. 

Nadir,  the  point  in  the  celestial  sphere  directly  heueath  our  feet, 
opposite  to  zenith. 

Nebulae,  217. 

Nebular  hypothesis,  not  atheistic,  182 ;  stated,  182  ;  confirmatory 
facts,  183 ;  objections  to,  185. 

Neptune,  elements  of,  175. 

Node,  the  point  in  which  an  orbit  intersects  the  ecliptic,  or  other 
plane  of  reference  ;  ascending,  descending,  line  of,  107. 

Occultation,  the  hiding  of  a  star,  planet,  or  satellite  by  the  inter- 
position of  a  nearer  body  of  greater  angular  magnitude. 

Opposition.  A  superior  planet  is  in  opposition  when  the  sun, 
earth,  and  the  planet  are  in  a  line,  the  earth  being  in  the  middle. 

Orbit,  the  path  of  a  planet,  comet,  or  meteor  around  the  sun,  or  of 
a  satellite  around  a  primary;  inclination  of,  106;  earth's,  seen 
from  the  stars,  70. 

Outline  for  students,  276. 

Parallax,  the  difference  of  direction  of  a  heavenly  body  as  seen 
from  two  points,  as  the  centre  of  the  earth  and  some  point  of  its 
surface,  69. 

Parallels,  imaginary  circles  on  the  earth  or  in  the  heavens  parallel 
to  the  equator,  having  the  poles  for  their  centre. 

Perigee,  nearest  the  earth :  said  of  a  point  in  an  orbit. 

Perihelion,  the  point  of  an  orbit  nearest  the  sun. 

Periodic  time,  time  of  a  planet's,  comet's,  or  satellite's  revolution. 

Personal  equation,  65. 

Perturbation,  the  effect  of  the  attractions  of  the  planets  or  other 


GLOSSARY  AND  INDEX.  283 

bodies  upon  each  other,  disturbing  their  regnlar  motion  ;  of  Sat- 
urn and  Jupiter,  11 ;  of  asteroids,  13 ;  of  Uranus  and  Neptune,  176. 

Phases,  the  portions  of  the  illumiuated  half  of  the  moon  or  infe- 
rior planet,  as  seen  from  the  earth,  called  crescent,  half,  full,  and 
gibbous. 

Photosphere  of  the  sun,  89. 

Planet  (a  icanderer),  as  seen  from  space,  99  ;  speed  of,  101 ;  size  of, 
102 ;  movements  retrograde  and  direct,  112. 

Pointers,  the,  197. 

Pole,  North,  movement  of,  198. 

Poles,  the  extremities  of  an  imaginary  line  on  which  a  celestial 
body  rotates. 

Quadrant,  the  fourth  part  of  the  circumference  of  a  circle,  or  90°. 

Quadrature,  a  position  of  the  moon  or  other  body  when  90°  from 
the  sun. 

Radiant  point,  that  point  of  the  heavens  from  which  meteors  seem 
to  diverge,  118. 

Radius-vector,  an  imaginary  line  joiniug  the  sun  and  a  planet  or 
comet  in  any  part  of  its  orbit. 

Rain,  weight  of,  249. 

Reflecting  telescope,  44. 

Refracting  telescope,  43. 

Refraction,  a  bending  of  light  by  passing  through  any  medium,  as 
air,  water,  prism. 

Retrograde  motion,  the  apparent  movement  of  a  planet  from  east 
to  west  among  the  stars. 

Revolution,  the  movement  of  bodies  about  their  centre  of  gravity. 

Rotation,  the  motion  of  a  body  around  its  axis. 

Satellites,  smaller  bodies  revolving  around  planets  and  stars. 

Saturn,  elements  of,  167 ;  revolution  of,  168  ;  rings  of,  169 ;  decreas- 
ing, 171 ;  nature  of,  171 ;  satellites  of,  172. 

Seasons,  of  the  earth,  102  ;  of  other  planets,  105. 

Selenography  (lunograpky),  a  description  of  the  moon's  surface. 

Signs  of  the  zodiac,  the  twelve  equal  parts,  of  30°  each,  into  which 
the  zodiac  is  divided. 

Solar  system,  view  of,  100, 177. 

Solstices,  those  points  of  the  ecliptic  which  are  most  distant  from 
the  equator.  The  sun  passes  one  about  June  21st,  and  the  other 
about  December  21st,  giving  the  longest  days  and  nights. 

Spectroscope,  46. 

Spectrum  of  sun  and  metals,  50. 

Stars,  chemistry  of,  28;  distance  of,  70-73;  mode  of  naming,  196; 
number  of,  210  ;  double  and  multiple,  210;  colored,  214  ;  clusters 
of,  215 ;  variable,  220  ;  temporary,  new,  and  lost,  223 ;  movements 
of  lateral,  226 ;  in  line  of  sight,  269. 

Stationary  points,  places  iu  a  planet's  orbit  at  which  it  has  no  mo- 
tion among  the  stars. 


284  GLOSSARY  AND  INDEX. 

Stellar  system,  the,  195. 

Summary  of  recent  discoveries,  269. 

Sun,  fall  of  two  meteoric  bodies  into,  19;  light  from  contraction  of, 
20 ;  as  seen  from  planets,  79  ;  corona,  81 ;  hydrogen  flames  of,  84  ; 
condition  of,  89 ;  spots,  90 ;  experiments,  95 ;  apparent  path  among 
the  stars,  111 ;  power  of,  250. 

Symbols  used  in  astronomy,  275. 

Telescope,  refracting,  43 ;  reflecting,  44 ;  Cambridge  equatorial,  46. 

Telescopic  •work,  clusters,  210  ;  double  stars,  212. 

Temporary  stars,  223. 

Terminator,  the  boundary-line  between  light  and  darkness  on  the 
moon  or  a  planet. 

Tides,  146. 

Transit,  the  passage  of  an  object  across  some  fixed  line,  as  the  me- 
ridian, or  between  the  eye  of  an  observer  and  an  apparently 
larger  object,  as  that  of  Mercury  or  Venus  over  the  disk  of  the 
sun,  and  the  satellites  of  Jupiter  over  its  disk :  of  a  star,  65. 

Ultimate  force,  the,  249. 

Uranus,  elements  of,  173 ;  moons  of,  retrograde,  174 ;  perturbed  by 
Neptune,  176. 

Variable  stars,  220. 

Venus,  139. 

Vernier,  a  scale  to  measure  very  minute  distances. 

Vertical  circle,  one  that  passes  through  the  zenith  and  nadir  of  the 
celestial  sphere.  The  prime  vertical  circle  passes  through  the 
east  and  west  points  of  the  horizon. 

Vulcan,  discovery  of,  137. 

Worlds,  the,  and  the  Word,  teach  the  same  truth,  231-245. 

Year,  the,  length  of,  on  any  planet,  is  determined  by  the  periodic 
time. 

Zenith,  the  point  in  the  celestial  sphere  directly  overhead. 

Zodiac,  a  belt  18°  wide  encircling  the  heavens,  the  ecliptic  being  in 
the  middle.  In  this  belt  the  larger  planets  always  appear.  In 
the  older  astronomy  it  was  divided  into  twelve  parts  of  30° 
each,  called  signs  of  the  zodiac. 

Zodiacal  light,  80. 


TO  FIND  TM  i-i  STARS  IN  TH  i-i  SKY. 

Detach  any  of  the  following  maps,  appropriate  to  the  time 
of  year,  hold  it  between  you  and  a  lantern  out-of-doors,  and 
you  have  an  exact  miniature  of  the  sky.  Or,  better,  cut  squares 
of  suitable  sizes  from  the  four  sides  of  a  box ;  put  a  map  over 
each  aperture ;  provide  for  ventilation,  and  turn  the  box  over 
a  lamp  or  candle  out-of-doors.  Use  an  opera  glass  to  find  the 
smaller  stars,  if  one  is  accessible. 


Circumpolar  Constellations.    Always  visible.    In  this  position. — January  20th,  at 
10  o'clock ;  February  4th,  at  9  o'clock;  and  February  19th,  at  S o'clock. 


Algol  is  on  the  Meridian,  51°  South  of  Pole.— At  10  o'clock,  December  7th ;  9  o'clock- 
December  22d ;  8  o'clock,  January  5th. 


Capella  (45°  from  the  Pole)  and  Rigel  (100°)  are  on  the  Meridian  at  8  o'clock 
February  Tth,  9  o'clock  January  22d,  and  at  10  o'clock  January  7th. 


Regains  comes  on  the  Meridian,  T9°  south  from  the  Pole,  at  10  o'clock  March  23d, 
9  o'clock  April  Sth,  and  at  8  o'clock  April  23d. 


Arctnrns  comes  to  the  Meridian,  70°  from  the  Pole,  at  10  o'clock  May  25th, 
9  o'clock  June  9th,  and  at  S  o'clock  Jnne  25th. 

13 


Altair  comes  to  the  Meridian,  82°  from  the  Pole,  at  10  o'clock  P.M.  August  18tb,  at 
9  o'clock  September  2d,  and  at  S  o'clock  September  ISth. 


Fomalhaut  comes  to  the  Meridian,  only  17°  from  the  horizon,  at  S  o'clock  Novem- 
ber 4th. 


<&' 


14  DAY  USE 


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Renewed  books  are  subject  to  immediate  recall. 


LIBRARY 


Tel.  No.  642-3381 


LD21-35m-2,'71 
(P200lslO)476— A-32 


General  Library 

University  of  California 

Berkeley 


